[go: up one dir, main page]

CN114838560B - An air separation device for producing low-pressure oxygen and an operating method thereof - Google Patents

An air separation device for producing low-pressure oxygen and an operating method thereof Download PDF

Info

Publication number
CN114838560B
CN114838560B CN202210435203.8A CN202210435203A CN114838560B CN 114838560 B CN114838560 B CN 114838560B CN 202210435203 A CN202210435203 A CN 202210435203A CN 114838560 B CN114838560 B CN 114838560B
Authority
CN
China
Prior art keywords
air
heat exchanger
rectifying tower
expander
pipeline
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.)
Active
Application number
CN202210435203.8A
Other languages
Chinese (zh)
Other versions
CN114838560A (en
Inventor
莫方淑
任文
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.)
Sichuan Air Separation Plant Group Co ltd
Original Assignee
Sichuan Air Separation Plant Group Co 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 Sichuan Air Separation Plant Group Co ltd filed Critical Sichuan Air Separation Plant Group Co ltd
Priority to CN202210435203.8A priority Critical patent/CN114838560B/en
Publication of CN114838560A publication Critical patent/CN114838560A/en
Application granted granted Critical
Publication of CN114838560B publication Critical patent/CN114838560B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • 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
    • F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
    • F25J3/04303—Lachmann expansion, i.e. expanded into oxygen producing or low 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
    • F25J3/04006—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
    • F25J3/04054—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 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
    • F25J3/04078—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression
    • F25J3/0409—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression of oxygen
    • 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
    • F25J3/04078—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression
    • F25J3/04103—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression using solely hydrostatic liquid head
    • 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
    • F25J3/04109—Arrangements of compressors and /or their drivers
    • F25J3/04115—Arrangements of compressors and /or their drivers characterised by the type of prime driver, e.g. hot gas expander
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • 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
    • F25J3/04163—Hot end purification of the feed air
    • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
    • 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
    • F25J3/04163—Hot end purification of the feed air
    • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
    • F25J3/04175—Hot end purification of the feed air by adsorption of the impurities at a pressure of substantially more than the highest 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
    • F25J3/04151—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
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04375—Details relating to the work expansion, e.g. process parameter etc.
    • F25J3/04393—Details relating to the work expansion, e.g. process parameter etc. using multiple or multistage gas work expansion
    • 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
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04812—Different modes, i.e. "runs" of operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/04951—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/04951—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network
    • F25J3/04963—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network and inter-connecting equipment within or downstream of the fractionation unit(s)
    • 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
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
    • F25J2205/62—Purifying more than one feed stream in multiple adsorption vessels, e.g. for two feed streams at different pressures
    • 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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/50—Oxygen or special cases, e.g. isotope-mixtures or low purity O2
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2240/00—Processes or apparatus involving steps for expanding of process streams
    • F25J2240/02—Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
    • F25J2240/04—Multiple expansion turbines in parallel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2240/00—Processes or apparatus involving steps for expanding of process streams
    • F25J2240/40—Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
    • F25J2240/42—Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval the fluid being air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
    • F25J2245/40—Processes or apparatus involving steps for recycling of process streams the recycled stream being air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/40—One fluid being air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/42—One fluid being nitrogen

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Emergency Medicine (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

本发明提供了一种制取低压氧的空分装置及运行方法，包括相耦合的两套空分系统：第一空分系统包括第一空压机、第一膨胀机、第一换热器、第一精馏塔、第二精馏塔和第一液氧蒸发器；第二空分系统包括第二空压机、第二膨胀机、第二换热器、第三精馏塔、第四精馏塔和第二液氧蒸发器；其中，第一耦合通道连接第二空压机、第一换热器和第一精馏塔；第二耦合通道连接第一空压机、第二换热器连接和第二液氧蒸发器；第一空压机的排气压力高于第二空压机。该装置通过两套空分系统耦合，由第一空压机为两套空分系统的液氧蒸发器提供压力空气，第二空压机为两套空分系统提供精馏所需的低压空气，降低了运行能耗，提高了经济效益。

The present invention provides an air separation device and operation method for preparing low-pressure oxygen, comprising two coupled air separation systems: the first air separation system comprises a first air compressor, a first expander, a first heat exchanger, a first distillation tower, a second distillation tower and a first liquid oxygen evaporator; the second air separation system comprises a second air compressor, a second expander, a second heat exchanger, a third distillation tower, a fourth distillation tower and a second liquid oxygen evaporator; wherein the first coupling channel connects the second air compressor, the first heat exchanger and the first distillation tower; the second coupling channel connects the first air compressor, the second heat exchanger and the second liquid oxygen evaporator; the exhaust pressure of the first air compressor is higher than that of the second air compressor. The device is coupled by two air separation systems, the first air compressor provides pressurized air for the liquid oxygen evaporators of the two air separation systems, and the second air compressor provides the two air separation systems with low-pressure air required for distillation, thereby reducing operating energy consumption and improving economic benefits.

Description

Air separation device for preparing low-pressure oxygen and operation method
Technical Field
The invention relates to the technical field of low-temperature gas separation, in particular to an air separation device for preparing low-pressure oxygen and an operation method.
Background
In the traditional air separation process for preparing low-pressure oxygen by adopting a cryogenic process, when the required oxygen pressure is low, a common process of self-pressurizing and re-vaporizing and re-heating liquid oxygen is used for replacing an oxygen compressor with higher cost and relatively lower safety, and in order to efficiently vaporize and utilize the self-pressurizing liquid oxygen, air is required to reach a certain pressure, and the conventional configuration is as follows: when the oxygen production amount is large, an air booster is independently configured; when the oxygen production amount is small, if the booster is configured independently, the investment of the booster is large, and the booster with small flow is not suitable for selection and has low efficiency, so that the pressure of the raw material air compressor is directly increased to realize the efficient vaporization of the low-pressure liquid oxygen.
The raw material air compressor with higher pressure is directly configured to replace a supercharger, and the energy consumption of the device is increased and the operation cost is increased although the investment is economical and the device is simplified. Is not beneficial to enterprises to control the production cost of products and improves the market competitiveness of the products.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides an air separation device for preparing low-pressure oxygen and an operation method thereof, the device is coupled with a first air separation system and a second air separation system, the first air compressor supplies pressure air for liquid oxygen evaporators of the two sets of air separation systems, the second air compressor supplies low-pressure air required by rectification for the two sets of air separation systems, the problem that the two sets of air separation systems are required to be provided with air compressors with higher pressure according to the traditional process is solved, the operation energy consumption is high, and the overall economic benefit is improved.
In order to achieve the above purpose, the invention adopts the following technical scheme:
An air separation device for preparing low-pressure oxygen comprises a first air separation system and a second air separation system:
The first air separation system comprises a first air compressor, a first expander, a first heat exchanger, a first rectifying tower, a second rectifying tower, a first liquid oxygen evaporator, a first air pipeline and a second air pipeline;
The first air pipeline and the second air pipeline are connected with the outlet end of the first air compressor, the first air pipeline is connected to the first liquid oxygen evaporator after passing through the first heat exchanger, and the second air pipeline is connected to the second rectifying tower after passing through the first expander and the first heat exchanger;
the second air separation system comprises a second air compressor, a second expander, a second heat exchanger, a third rectifying tower, a fourth rectifying tower, a second liquid oxygen evaporator, a fourth air pipeline and a fifth air pipeline;
the fourth air pipeline and the fifth air pipeline are connected with the outlet end of the second air compressor; the fourth air pipeline is connected to the third rectifying tower through the second heat exchanger; the fifth air pipeline is connected to a fourth rectifying tower after passing through the second expander and the second heat exchanger;
the first space division system and the second space division system are connected through a first coupling channel and a second coupling channel;
The inlet end of the first coupling channel is connected with the second air compressor and is connected to the first rectifying tower through the first heat exchanger; the inlet end of the second coupling channel is connected with the first air compressor and connected to the second liquid oxygen evaporator through the second heat exchanger;
the exhaust pressure of the first air compressor is higher than that of the second air compressor.
In one embodiment of the present application, the first air separation system further includes a third air pipe, which is sequentially connected to the first air compressor, the first heat exchanger, and the first rectifying tower;
And/or the number of the groups of groups,
The second air separation system further comprises a third expander, a sixth air pipeline and a seventh air pipeline;
The sixth air pipeline is sequentially connected with the second air compressor, the compression end of the third expander, the second heat exchanger and the second liquid oxygen evaporator;
And the seventh air pipeline is sequentially connected with the expansion ends of the second air compressor, the second heat exchanger and the third expander, the second heat exchanger and the fourth rectifying tower.
In one embodiment of the present application, the third air duct, the fifth air duct, the sixth air duct, the seventh air duct, the first coupling channel and the second coupling channel are each provided with a shut-off valve.
In one embodiment of the application, the first coupling channel merges with the third air duct portion a common duct, the second coupling channel merges with the sixth air duct portion a common duct, and the fifth air duct merges with a seventh air duct portion a common duct.
In one embodiment of the present application, the exhaust pressure of the first air compressor is 700-720 kpa, and the exhaust pressure of the second air compressor is 560-620 kpa.
In one embodiment of the application, the second expander and the third expander are operated differently and not simultaneously.
In one embodiment of the present application, the first air separation system further includes a first condensation evaporator, where the first rectifying tower, the first condensation evaporator and the second rectifying tower are sequentially disposed from bottom to top, and an evaporation side liquid outlet of the first condensation evaporator is connected with an evaporation side of the first liquid oxygen evaporator;
the second air separation system further comprises a second condensation evaporator, the third rectifying tower, the second condensation evaporator and the fourth rectifying tower are sequentially arranged from bottom to top, and the evaporation side liquid outlet of the second condensation evaporator is connected with the evaporation side of the second liquid oxygen evaporator.
An operation method of an air separation plant for preparing low-pressure oxygen, wherein the air separation plant is the air separation plant, the operation method comprises a first operation mode, and the first operation mode comprises the following steps:
step S100: opening a first coupling channel and a second coupling channel;
step S200: the first air separation system operates, and raw material air is compressed by a first air compressor to obtain compressed air A;
Step S210: the first part of the compressed air A enters a second coupling channel, is cooled by a second heat exchanger and is sent to the condensation side of a second liquid oxygen evaporator;
Step S220: the second part of the compressed air A enters a first air pipeline, is cooled by a first heat exchanger and is sent to the condensation side of a first liquid oxygen evaporator;
step S230: the third part of the compressed air A enters a second air pipeline, sequentially passes through the compression end of the first expander, the first heat exchanger, the expansion end of the first expander and the first heat exchanger, and then is sent to a second rectifying tower to participate in rectification;
step S300: the second air separation system operates, and raw material air is compressed by a second air compressor to obtain compressed air B;
step S310: a first part of the compressed air B enters a first coupling channel, is cooled by a first heat exchanger and then is sent into a first rectifying tower to participate in rectification;
step S320: the second part of the compressed air B enters a fourth air pipeline, is cooled by a second heat exchanger and then is sent into a third rectifying tower to participate in rectification;
step S330: and the third part of the compressed air B enters a fifth air pipeline, sequentially enters a compression end of the second expander, the second heat exchanger, an expansion end of the second expander and the second heat exchanger, and then enters a fourth rectifying tower to participate in rectification.
In an embodiment of the present application, the air separation apparatus is the air separation apparatus described above, and the operation method further includes a second operation mode, where the second operation mode includes the following steps:
step M100: closing the first coupling channel and the second coupling channel;
Step M200: the first air separation system operates, and raw material air is compressed by a first air compressor to obtain compressed air C;
Step M210: a first part of the compressed air C enters a third air pipeline, is cooled by a first heat exchanger and then is sent into a first rectifying tower to participate in rectification;
step M220: the second part of the compressed air C enters a first air pipeline, is cooled by a first heat exchanger and is sent to the condensation side of a first liquid oxygen evaporator;
Step M230: the third part of the compressed air C enters a second air pipeline, is sequentially processed by a compression end of a first expander, a first heat exchanger, an expansion end of the first expander and the first heat exchanger, and is sent to a second rectifying tower to participate in rectification;
And/or the number of the groups of groups,
Step M300: the second air separation system operates, and raw material air is compressed by a second air compressor to obtain compressed air D;
step M310: the first part of the compressed air D enters a fourth air pipeline, is cooled by a second heat exchanger and then is sent into a third rectifying tower to participate in rectification;
Step M320: the second part of the compressed air D enters a sixth air pipeline, is pressurized by a compression end of a third expander and cooled by a second heat exchanger in sequence, and is then sent to the condensation side of a second liquid oxygen evaporator;
Step M330: and the third part of the compressed air D enters a seventh air pipeline, sequentially passes through the second heat exchanger, the expansion end of the third expander and the second heat exchanger, and then is sent into a fourth rectifying tower to participate in rectification.
In one embodiment of the present application, the third air duct, the sixth air duct, the seventh air duct and the third expander are all in a closed state when the first operation mode is operated.
Compared with the prior art, the invention has the beneficial effects that:
1. According to the air separation device for preparing low-pressure oxygen, the first air separation system and the second air separation system are arranged for coupling, and the first air compressor with higher matched pressure supplies pressure air for the liquid oxygen evaporators of the two sets of air separation systems to exchange heat with low-pressure liquid oxygen; the second air compressor with lower matched pressure provides low-pressure air required by rectification for the two sets of air separation systems; in the two sets of air separation systems, the operation requirements of the two sets of air separation systems can be met only by configuring higher pressure of the first air compressor, and compared with the traditional process, the configuration of the second air compressor in the second air separation system can be reduced, so that the purposes of reducing the operation energy consumption and improving the economic benefit are achieved.
2. The first air separation system is provided with a third air pipeline, and the second air separation system is provided with a third expander, a sixth air pipeline and a seventh air pipeline, so that the two sets of air separation systems can be coupled to operate or independently operate; and the independent operation energy consumption of the second air separation system is slightly lower than that of the scheme of higher pressure matched with the traditional air compressor.
3. The air separation device provides an upgrading and reforming scheme for preparing low-pressure oxygen, when an original air separation system (a first air separation system) is matched with an air compressor with higher pressure and a new air separation system is needed, a second air separation system can be used as the new air separation system, and the two air separation systems are coupled through a first coupling channel and a second coupling channel; the air compressor of the second air separation system is configured with an air compressor with the exhaust pressure lower than that of the first air separation system, so that the coupling operation can effectively ensure that the two sets of air separation systems normally operate to prepare the required low-pressure oxygen, and the overall operation energy consumption can be effectively reduced; in addition, the two sets of space division systems can independently operate, are convenient to overhaul and maintain, and have strong adaptability.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic process flow diagram of a hollow division device according to an embodiment of the invention.
FIG. 2 is a schematic process flow diagram of a hollow division apparatus according to an embodiment of the invention.
Reference numerals:
100. a first air separation system;
110. a first air compressor; 111. a first air duct; 112. a second air duct; 113. a third air duct; 120. a first expander; 130. a first heat exchanger; 140. a first rectifying column; 150. a second rectifying column; 160. a first liquid oxygen evaporator; 170. a first condensing evaporator;
200. a second space division system;
210. a second air compressor; 211. a fourth air duct; 212. a fifth air duct; 213. a sixth air duct; 214. a seventh air duct; 220. a second expander; 230. a third expander; 240. a second heat exchanger; 250. a third rectifying column; 260. a fourth rectifying column; 270. a second liquid oxygen evaporator; 280. a second condensing evaporator;
300. a first coupling channel;
400. a second coupling channel;
500. And a shut-off valve.
Detailed Description
Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in numerous different ways without departing from the spirit or scope of the embodiments of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Example 1
As shown in fig. 1, an embodiment of the present invention provides an air separation plant for producing low pressure oxygen, which includes a first air separation system 100 and a second air separation system 200 coupled to each other.
The first air separation system 100 includes a first air compressor 110, a first expander 120, a first heat exchanger 130, a first rectifying tower 140, a second rectifying tower 150, a first liquid oxygen evaporator 160, a first condensation evaporator 170, and the like.
The outlet end of the first air compressor 110 is connected to an air duct, which is divided into a first air duct 111 and a second air duct 112. The first air pipe 111 passes through the first heat exchanger 130 and then is connected to the condensing side of the first liquid oxygen evaporator 160. That is, a part of the compressed air of the first air compressor 110 is cooled in the first air duct 111 by the first heat exchanger 130, cooled to a certain temperature, and then sent to the condensation side of the first liquid oxygen evaporator 160, condensed by the liquid oxygen in the first liquid oxygen evaporator 160, and sent to the first rectifying tower 130 to participate in rectification. The second air duct 112 is connected to the second rectification column 150 after passing through the first expander 120 and the first heat exchanger 130. Specifically, the other part of compressed air of the first air compressor 110 enters the pressurizing end of the first expander 120 through the second air pipeline 112 for pressurization, is cooled by the first heat exchanger 130 after being pressurized, is sent to the expansion end of the first expander 120 for expansion refrigeration after being cooled to a certain temperature, and is returned to the first heat exchanger 130 for cooling again, and the cooled air is sent to the second rectifying tower 150 for rectification.
The first rectifying tower 140, the first condensation evaporator 170 and the second rectifying tower 150 are sequentially arranged from bottom to top, and an evaporation side liquid outlet at the lower part of the first condensation evaporator 170 is connected with an evaporation side inlet of the first liquid oxygen evaporator 160 through a pipeline. Liquid oxygen obtained at the bottom of the second rectifying tower 150 enters a first condensing evaporator 170, and a part of liquid oxygen is pumped out of the first condensing evaporator 170 and enters the first liquid oxygen evaporator 160, so as to obtain liquid oxygen and obtain low-pressure oxygen through self-pressurization vaporization.
The second air separation system 200 includes a second air compressor 210, a second expander 220, a second heat exchanger 240, a third rectification column 250, a fourth rectification column 260, a second liquid oxygen evaporator 270, a second condensation evaporator 280, and the like.
The outlet end of the second air compressor 210 is connected to an air duct, which is divided into a fourth air duct 211 and a fifth air duct 212. The fourth air pipe 211 is connected to the third rectification column 250 after passing through the second heat exchanger 240. That is, a part of the compressed air of the second air compressor 210 is cooled in the fourth air pipe 211 by the second heat exchanger 240, cooled to a certain temperature, and then sent to the third rectification 250 to participate in the rectification. The fifth air line 212 is connected to the fourth rectifying column 260 after passing through the second expander 220 and the second heat exchanger 240. Specifically, the other part of compressed air of the second air compressor 210 enters the pressurizing end of the second expander 220 through the fifth air pipe 121 to be pressurized, the pressurized compressed air enters the second heat exchanger 240 to be cooled, the cooled compressed air is sent to the expansion end of the second expander 220 to be expanded and refrigerated after being cooled to a certain temperature, the expanded air returns to the second heat exchanger 240 to be cooled again, and the cooled air is sent to the fourth rectifying tower 260 to participate in rectification.
The third rectifying tower 250, the second condensing evaporator 280 and the fourth rectifying tower 260 are sequentially arranged from bottom to top, wherein the evaporation side liquid outlet of the second condensing evaporator 280 is connected with the evaporation side liquid inlet of the second liquid oxygen evaporator 270. The liquid oxygen obtained at the bottom of the fourth rectifying tower 260 enters a second condensing evaporator 280, and a part of the liquid oxygen is pumped out of the second condensing evaporator 280 and enters the second liquid oxygen evaporator 270, so as to obtain liquid oxygen and obtain low-pressure oxygen through self-pressurization vaporization.
The first space division system 100 and the second space division system 200 are connected and coupled through a first coupling channel 300 and a second coupling channel 400.
The inlet end of the first coupling channel 300 is connected to the outlet end of the second air compressor 210 in the second air separation system 200, then enters the first air separation system 100, passes through the first heat exchanger 130, and is connected to the first rectifying tower 140. Namely, the raw material compressed air from the second air separation system 200 enters the first air separation system 100, is cooled to a certain temperature in the first air separation system 100 through the first heat exchanger 130, and is sent to the first rectifying tower 140 to participate in rectification.
The inlet end of the second coupling channel 400 is connected to the outlet end of the first air compressor 110 in the first air separation system 100, then enters the second air separation system 200, passes through the second heat exchanger 240, and is connected to the second liquid oxygen evaporator 270. The raw material compressed air of the first air separation system 100 enters the second air separation system 200, is cooled to a certain temperature in the second air separation system 200 by the second heat exchanger 240, is sent to the condensation side of the second liquid oxygen evaporator 270, is condensed by liquid oxygen in the second liquid oxygen evaporator 270, and is sent to the third rectifying tower 150 to participate in rectification.
The discharge pressure of the first air compressor 110 should be higher than the discharge pressure of the second air compressor 210. The exhaust pressure of the first air compressor 110 may be configured to be 720kPa (a), and the exhaust pressure of the second air compressor 210 may be configured to be 560kPa (a).
The outlet ends of the first air compressor 110 and the second air compressor 210 are respectively provided with a pretreatment system, and pre-cooling, drying, purifying treatment and the like are performed on the compressed raw air so as to clean and dry the obtained compressed air.
In operation, the first air compressor 110 with higher exhaust pressure is configured to provide pressure air for the liquid oxygen heat exchangers of the two sets of air separation systems so as to exchange heat with low-pressure liquid oxygen; the second air compressor 210 with lower exhaust pressure is configured to provide low-pressure air required for rectification for the two sets of air separation systems. Namely, in the two sets of air separation systems, the operation requirements of the two sets of air separation systems can be met only by configuring the first air compressor 110 with higher exhaust pressure, and compared with the traditional process, the configuration of the second air compressor 210 in the second air separation system 200 is reduced, so that the purposes of reducing the operation energy consumption and improving the economic benefit are realized.
The operation method of the air separation apparatus includes a first operation mode, where the first air separation system 100 and the second air separation system 200 are coupled to operate. Specifically, taking the oxygen pressure requirement of 220kPa (a) as an example, the first mode of operation comprises the following operational steps:
Step S100: the first coupling channel 300 and the second coupling channel 400 are opened and both coupling channels are put into use.
Step S200: the first air separation system 100 is operated, and raw air is compressed to a pressure of about 720kPa (a) by the first air compressor 110, and is treated by the pretreatment system to obtain clean and dry compressed air a having a pressure of about 695kPa (a).
Step S210: the first part of the compressed air A enters the second air separation system 200 through the second coupling channel 400, is cooled in the second air separation system 200 through the second heat exchanger 240, is cooled to a certain temperature, is sent to the condensation side of the second liquid oxygen evaporator 270, is condensed through low-pressure liquid oxygen, and is sent to the third rectifying tower to participate in rectification.
Step S220: the second part of the compressed air A enters the first air pipeline 111, is cooled by the first heat exchanger 130, is sent to the condensation side of the first liquid oxygen evaporator 160 after being cooled to a certain temperature, is condensed by the liquid oxygen in the first liquid oxygen evaporator 160, and is sent to the first rectifying tower 140 to participate in rectification.
Step S230: the third part of the compressed air A enters the second air pipeline 112, is pressurized by the compression end of the first expander 120, enters the first heat exchanger 130 for cooling after being pressurized, is sent to the expansion end of the first expander 120 for expansion refrigeration after being cooled to a certain temperature, and is sent to the second rectifying tower 150 for rectification after being cooled after being returned to the first heat exchanger for cooling.
Step S300: the second air separation system 200 operates simultaneously with the first air separation system 100; the raw air is compressed to a pressure of about 560kPa (a) by the second air compressor 210 and is treated by the pretreatment system to obtain clean and dry compressed air B having a pressure of about 535kPa (a).
Step S310: a first part of the compressed air B enters the first air separation system 100 through the first coupling channel 300, is cooled in the first air separation system 100 by the first heat exchanger 130, and is sent into the first rectifying tower 140 to participate in rectification.
Step S320: the second part of the compressed air B enters a fourth air pipeline 211, is cooled by a second heat exchanger 240, is cooled to a certain temperature, and is sent into a third rectifying tower 250 to participate in rectification.
Step S330: the third part of the compressed air B enters the fifth air pipeline 212, is pressurized by the compression end of the second expander 230, enters the second heat exchanger 240 for cooling after being pressurized, is sent to the expansion end of the second expander 230 for expansion refrigeration after being cooled to a certain temperature, and returns to the second heat exchanger 240 for being cooled again, and the cooled air is sent to the fourth rectifying tower 260 for rectification.
Further comprising step S240: liquid oxygen obtained from the bottom of the second rectifying tower 150 enters the first condensing evaporator 170, and a part of liquid oxygen is pumped to the evaporation side of the first liquid oxygen evaporator 160 and exchanges heat with the second part of the compressed air A to prepare low-pressure oxygen and liquid oxygen.
Correspondingly, the method also comprises the step S340: the liquid oxygen obtained from the bottom of the fourth rectifying tower 260 enters the second condensing evaporator 280, and a part of the liquid oxygen is pumped to the evaporation side of the second liquid oxygen evaporator 270 and exchanges heat with the first part of the compressed air A to prepare low-pressure oxygen and liquid oxygen.
Example two
As shown in fig. 2, the present embodiment provides an air separation plant for producing low-pressure oxygen, which is different from the air separation plant described in the first embodiment in that the first air separation system 100 further includes a third air duct 113, and/or the second air separation system 200 further includes a third expander 230, a sixth air duct 213, and a seventh air duct 214.
The third air pipe 113 is sequentially connected to the first air compressor 110, the first heat exchanger 130, and the first rectifying tower 140. Namely, one end of the third air duct 113 is connected to the outlet end of the first air compressor 110, exchanges heat through the first heat exchanger 130, and is then connected to the first rectifying tower 140.
The sixth air pipe 213 is connected to the outlet end of the second air compressor 210, the compression end of the third expander 230, the second heat exchanger 240 and the condensation side of the second liquid oxygen evaporator 270 in order, and pressurizes and cools part of the compressed air of the second air compressor 210 and sends the cooled air to the second liquid oxygen evaporator 270.
The seventh air pipe 214 is connected to the outlet end of the second air compressor 210, the second heat exchanger 240, the expansion end of the third expander 230, the second heat exchanger 240, and the fourth rectifying column 260 in this order. Namely, after being cooled by the second heat exchanger 240, part of the compressed air of the second air compressor 210 is expanded and refrigerated by the third expander 230, and then returned to the second heat exchanger 240 for cooling again, and after being cooled again, the compressed air is sent to the fourth rectifying tower 260 to participate in rectification.
The third air duct 113, the fifth air duct 212, the sixth air duct 213, the seventh air duct 214, the first coupling passage 300, and the second coupling passage 400 are each provided with a shut-off valve 500.
The first coupling channel 300 may be connected to the third air duct 113 to join the first air separation system 100 and share a common pipeline. The third air duct 113 is provided with a shut-off valve 500 before the junction is connected, and the shut-off valve 500 on the first coupling passage 300 and the third air duct 113 are alternatively opened, not simultaneously opened.
The second coupling passage 400 may be joined to the sixth air conduit 213 after entering the second air separation system 200, where the junction is located after the boost end of the third expander 230 and before entering the second heat exchanger 240. The fifth air duct 212 joins the seventh air duct 214 after the pressurized end of the second expander 220. The second coupling channel 400, the fifth air duct 212 and the sixth air duct 213, the seventh air duct 214 do not operate at the same time.
The first coupling channel 300 is partially converged with the third air pipeline 113, the second coupling channel 400 is partially converged with the sixth air pipeline 213, the fifth air pipeline 212 is partially converged with the seventh air pipeline 214, and the pipelines are shared, so that the pipeline arrangement is effectively simplified, the pipe consumption is reduced, and the later maintenance is facilitated.
In the air separation device of this embodiment, two sets of air separation systems may be coupled to each other or may be operated separately. In order to ensure that both operation modes can be operated normally, it is preferable to configure the discharge pressure of the first air compressor 110 to be 720kPa (a) and the discharge pressure of the second air compressor 210 to be 605kPa (a).
The air separation device operation method of the present embodiment includes two operation modes, namely a first operation mode and a second operation mode.
The first operation mode is a coupling operation mode of the first air separation system 100 and the second air separation system 200, and a specific operation method is described in the first embodiment. When operating in the first mode of operation, the third air line 113, the sixth air line 213, the seventh air management 214, and the third expander 230 are all in a closed state.
The second operation mode is a mode in which the first air separation system 100 and the second air separation system 200 independently select one operation or independently operate simultaneously. Specifically, taking the oxygen pressure requirement of 220kPa (a) as an example, the second mode of operation comprises the following operational steps:
step M100: the first coupling channel 300 and the second coupling channel 400 are closed, and the first space division system 100 and the second space division system 200 are operated independently of each other, alternatively operated, or simultaneously operated independently.
Step M200: the first air separation system 100 operates independently, and raw air is compressed to a pressure of about 720kPa (a) by the first air compressor 110, and pre-cooled, dried and purified by the pretreatment system to obtain clean and dry compressed air C having a pressure of about 695kPa (a).
Step M210: a first part of the compressed air C enters the third air pipeline 113, is cooled by the first heat exchanger 130, and is sent to the first rectifying tower 140 to participate in rectification after being cooled.
Step M220: the second part of the compressed air C enters the first air pipeline 111, is cooled by the first heat exchanger 130, enters the condensation side of the first liquid oxygen evaporator 160 after being cooled, and enters the first rectifying tower 140 to participate in rectification after being condensed by liquid oxygen.
Step M230: the third part of the compressed air C enters the second air pipeline 112, then sequentially enters the compression end of the first expander 120 for pressurization, enters the first heat exchanger 130 for cooling after pressurization, enters the expansion end of the first expander 120 for expansion refrigeration after cooling, returns to the first heat exchanger 130 for cooling again after expansion, and enters the second rectifying tower 150 for rectification after cooling again.
And/or the number of the groups of groups,
Step M300: the second air separation system 200 operates independently, and raw air is compressed to a pressure of about 605kPa (a) by the second air compressor 210, and pre-cooled and dried by the pretreatment system, and purified, to obtain dry and clean compressed air D, the pressure of which is about 575kPa (a).
Step M310: the first part of the compressed air D enters a fourth air pipeline 211, is cooled by a second heat exchanger 240, is cooled to a certain temperature, and is sent to a third rectifying tower 250 to participate in rectification.
Step M320: the second part of the compressed air D enters the sixth air pipeline 213, is pressurized to 695kPa (a) by the pressurizing end of the third expander 230, is cooled by the second heat exchanger 240, is cooled to a certain temperature, and then is sent to the condensation side of the second liquid oxygen evaporator 270, and is sent to the third rectifying tower 250 to participate in rectification after being condensed by liquid oxygen.
Step M330: the third part of the compressed air D enters the seventh air pipeline 214, is cooled to a certain temperature by the second heat exchanger 240, is sent to the expansion end of the third expander 230 for expansion refrigeration, is returned to the second heat exchanger 240 for cooling again after expansion, and is sent to the fourth rectifying tower 260 for rectification.
The second expander 220 and the third expander 230 are two expanders configured differently, and have different functions in terms of technology, and are respectively coupled with the second heat exchanger 240. The second expander 220 satisfies the requirement when the second air separation system 200 is coupled to the first air separation system 100 for operation (first mode of operation), and the third expander 230 satisfies the requirement when the second air separation system 200 is independently operated.
As shown in Table 1, the operation of the conventional air separation system was compared with that of the second air separation system 200 of the present application by taking the second air separation system 200 as an example, which has an oxygen yield of 2500Nm 3/h, an oxygen purity of 99.6% and a pressure of 220kPa (A).
Table 1 comparison of the second space division system with the conventional space division system
As can be seen from Table 1, when the two sets of air separation systems are coupled and operated, the raw material air pressure of the second air separation system 200 can be reduced by about 160kPa compared with the traditional air separation system, the compression power of the raw material air is reduced by more than 10%, and the energy-saving effect is remarkable.
The two sets of air separation systems can independently operate, and when the first air separation system 100 is stopped for maintenance, the second air separation system 200 can independently operate, and when the second air separation system 200 is independently operated, the raw material air compression power is lower than that of the traditional air separation system.
In summary, the application designs that the first air separation system 100 (original traditional air separation system) is coupled with the second air separation system 200 (newly built air separation system), under the condition that the investment of power equipment is not additionally increased, the first air compressor 110 with higher pressure matched with the first air separation system 100 can provide pressure air for the liquid oxygen heat exchangers of two sets of air separation systems, the second air compressor 210 with lower pressure matched with the second air separation system 200 can provide low-pressure air required by rectification for the two sets of air separation systems, the problem that the operation energy consumption is high when the air compressor with higher pressure is configured for the newly built air separation system according to the traditional scheme is solved, the second air separation system 200 is coupled to operate or independently operated, the operation energy consumption is reduced, and the economic benefit can be effectively improved.
The protection scope of the present application should be defined by the claims, and the above description is only exemplary embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art who is within the technical scope of the present application should be covered by the protection scope of the present application without any changes or substitutions that are conceivable by creative efforts.

Claims (10)

1. An air separation device for preparing low-pressure oxygen is characterized by comprising a first air separation system and a second air separation system:
The first air separation system comprises a first air compressor, a first expander, a first heat exchanger, a first rectifying tower, a second rectifying tower, a first liquid oxygen evaporator, a first air pipeline and a second air pipeline;
The first air pipeline and the second air pipeline are connected with the outlet end of the first air compressor, the first air pipeline is connected to the first liquid oxygen evaporator after passing through the first heat exchanger, and the second air pipeline is connected to the second rectifying tower after passing through the first expander and the first heat exchanger;
the second air separation system comprises a second air compressor, a second expander, a second heat exchanger, a third rectifying tower, a fourth rectifying tower, a second liquid oxygen evaporator, a fourth air pipeline and a fifth air pipeline;
the fourth air pipeline and the fifth air pipeline are connected with the outlet end of the second air compressor; the fourth air pipeline is connected to the third rectifying tower through the second heat exchanger; the fifth air pipeline is connected to a fourth rectifying tower after passing through the second expander and the second heat exchanger;
the first space division system and the second space division system are connected through a first coupling channel and a second coupling channel;
The inlet end of the first coupling channel is connected with the second air compressor and is connected to the first rectifying tower through the first heat exchanger; the inlet end of the second coupling channel is connected with the first air compressor and connected to the second liquid oxygen evaporator through the second heat exchanger;
the exhaust pressure of the first air compressor is higher than that of the second air compressor.
2. The air separation plant for producing low-pressure oxygen according to claim 1, wherein the first air separation system further comprises a third air pipeline, and the third air pipeline is sequentially connected with the first air compressor, the first heat exchanger and the first rectifying tower;
And/or the number of the groups of groups,
The second air separation system further comprises a third expander, a sixth air pipeline and a seventh air pipeline;
The sixth air pipeline is sequentially connected with the second air compressor, the compression end of the third expander, the second heat exchanger and the second liquid oxygen evaporator;
And the seventh air pipeline is sequentially connected with the expansion ends of the second air compressor, the second heat exchanger and the third expander, the second heat exchanger and the fourth rectifying tower.
3. The air separation unit for preparing low-pressure oxygen according to claim 2, wherein the third air pipe, the fifth air pipe, the sixth air pipe, the seventh air pipe, the first coupling channel and the second coupling channel are provided with shut-off valves.
4. A low pressure oxygen producing air separation plant according to claim 3 wherein the first coupling passage merges with the third air duct portion into a common duct, the second coupling passage merges with the sixth air duct portion into a common duct, and the fifth air duct merges with the seventh air duct portion into a common duct.
5. The air separation device for preparing low-pressure oxygen according to any one of claims 1 to 4, wherein the exhaust pressure of the first air compressor is 700 to 720kpa, and the exhaust pressure of the second air compressor is 560 to 620kpa.
6. The apparatus according to claim 2, wherein the second expander and the third expander are operated differently and not simultaneously.
7. A space division apparatus for producing low pressure oxygen according to any one of claims 1 to 3, wherein:
The first air separation system further comprises a first condensation evaporator, the first rectifying tower, the first condensation evaporator and the second rectifying tower are sequentially arranged from bottom to top, and an evaporation side liquid outlet of the first condensation evaporator is connected with the evaporation side of the first liquid oxygen evaporator;
the second air separation system further comprises a second condensation evaporator, the third rectifying tower, the second condensation evaporator and the fourth rectifying tower are sequentially arranged from bottom to top, and the evaporation side liquid outlet of the second condensation evaporator is connected with the evaporation side of the second liquid oxygen evaporator.
8. An air separation plant operating method for the production of low pressure oxygen, characterized in that the air separation plant is an air separation plant according to any one of claims 1 to 7, comprising a first operating mode comprising the steps of:
step S100: opening a first coupling channel and a second coupling channel;
step S200: the first air separation system operates, and raw material air is compressed by a first air compressor to obtain compressed air A;
Step S210: the first part of the compressed air A enters a second coupling channel, is cooled by a second heat exchanger and is sent to the condensation side of a second liquid oxygen evaporator;
Step S220: the second part of the compressed air A enters a first air pipeline, is cooled by a first heat exchanger and is sent to the condensation side of a first liquid oxygen evaporator;
Step S230: the third part of the compressed air A enters a second air pipeline, sequentially passes through the compression end of the first expander, the first heat exchanger, the expansion end of the first expander and the first heat exchanger, and then is sent into a second rectifying tower to participate in rectification;
step S300: the second air separation system operates, and raw material air is compressed by a second air compressor to obtain compressed air B;
step S310: a first part of the compressed air B enters a first coupling channel, is cooled by a first heat exchanger and then is sent into a first rectifying tower to participate in rectification;
step S320: the second part of the compressed air B enters a fourth air pipeline, is cooled by a second heat exchanger and then is sent into a third rectifying tower to participate in rectification;
step S330: and the third part of the compressed air B enters a fifth air pipeline, sequentially enters a compression end of the second expander, the second heat exchanger, an expansion end of the second expander and the second heat exchanger, and then enters a fourth rectifying tower to participate in rectification.
9. The method of operating a low pressure oxygen producing air separation plant according to claim 8, wherein the air separation plant is any one of claims 2 to 4, the method further comprising a second mode of operation comprising the steps of:
step M100: closing the first coupling channel and the second coupling channel;
Step M200: the first air separation system operates, and raw material air is compressed by a first air compressor to obtain compressed air C;
Step M210: a first part of the compressed air C enters a third air pipeline, is cooled by a first heat exchanger and then is sent into a first rectifying tower to participate in rectification;
step M220: the second part of the compressed air C enters a first air pipeline, is cooled by a first heat exchanger and is sent to the condensation side of a first liquid oxygen evaporator;
Step M230: the third part of the compressed air C enters a second air pipeline, is sequentially processed by a compression end of a first expander, a first heat exchanger, an expansion end of the first expander and the first heat exchanger, and is sent to a second rectifying tower to participate in rectification;
And/or the number of the groups of groups,
Step M300: the second air separation system operates, and raw material air is compressed by a second air compressor to obtain compressed air D;
step M310: the first part of the compressed air D enters a fourth air pipeline, is cooled by a second heat exchanger and then is sent into a third rectifying tower to participate in rectification;
Step M320: the second part of the compressed air D enters a sixth air pipeline, is pressurized by a compression end of a third expander and cooled by a second heat exchanger in sequence, and is then sent to the condensation side of a second liquid oxygen evaporator;
Step M330: and the third part of the compressed air D enters a seventh air pipeline, sequentially passes through the second heat exchanger, the expansion end of the third expander and the second heat exchanger, and then is sent into a fourth rectifying tower to participate in rectification.
10. The method of claim 9, wherein the third air line, the sixth air line, the seventh air line, and the third expander are all closed when the first mode of operation is performed.
CN202210435203.8A 2022-04-24 2022-04-24 An air separation device for producing low-pressure oxygen and an operating method thereof Active CN114838560B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210435203.8A CN114838560B (en) 2022-04-24 2022-04-24 An air separation device for producing low-pressure oxygen and an operating method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210435203.8A CN114838560B (en) 2022-04-24 2022-04-24 An air separation device for producing low-pressure oxygen and an operating method thereof

Publications (2)

Publication Number Publication Date
CN114838560A CN114838560A (en) 2022-08-02
CN114838560B true CN114838560B (en) 2024-11-22

Family

ID=82565094

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210435203.8A Active CN114838560B (en) 2022-04-24 2022-04-24 An air separation device for producing low-pressure oxygen and an operating method thereof

Country Status (1)

Country Link
CN (1) CN114838560B (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN217560209U (en) * 2022-04-24 2022-10-11 四川空分设备(集团)有限责任公司 Air separation device for preparing low-pressure oxygen

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9124242D0 (en) * 1991-11-14 1992-01-08 Boc Group Plc Air separation
CN201589493U (en) * 2009-12-22 2010-09-22 四川空分设备(集团)有限责任公司 Device for reducing comprehensive energy consumption of air separation
CN101886871B (en) * 2010-08-04 2012-08-08 四川空分设备(集团)有限责任公司 Method and device for producing pressure oxygen by air separation
CN110207457B8 (en) * 2019-06-08 2023-12-29 苏州制氧机股份有限公司 Air separation equipment capable of preparing liquid nitrogen and application method thereof
CN114017990B (en) * 2021-11-05 2024-07-02 四川空分设备(集团)有限责任公司 Small air separation device for preparing low-pressure low-purity oxygen and medium-pressure nitrogen

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN217560209U (en) * 2022-04-24 2022-10-11 四川空分设备(集团)有限责任公司 Air separation device for preparing low-pressure oxygen

Also Published As

Publication number Publication date
CN114838560A (en) 2022-08-02

Similar Documents

Publication Publication Date Title
CN109157944B (en) Fractional cryogenic recovery system for VOCs (volatile organic compounds) of throttling expansion refrigeration
CN109140903B (en) Air separation system and air separation method utilizing cold energy of liquefied natural gas
CN111406192B (en) Cryogenic rectification method and apparatus for producing pressurized air by expander booster braked in conjunction with nitrogen expander
CN113562701B (en) A device and method for recovering by-product oxygen in hydrogen production from electrolyzed water by using low temperature method
CN106369935B (en) Air separation system and method utilizing pressure energy of high-pressure natural gas pipe network
CN108286870A (en) A kind of method that cryogenic rectification produces liquid
WO2024011780A1 (en) Low-temperature carbon capture coupling cold energy and waste heat gradient utilization system for lng-powered vessel
CN110553464A (en) CO cryogenic separation system and method for reducing nitrogen circulation energy consumption
CN214371298U (en) Carbon dioxide gathering liquefaction recovery device
CN217560209U (en) Air separation device for preparing low-pressure oxygen
CN206160625U (en) Utilize air separation system of high -pressure natural gas pipe network pressure ability
CN114838560B (en) An air separation device for producing low-pressure oxygen and an operating method thereof
CN206235085U (en) Liquid oxygen, liquid nitrogen exchange process units
CN114518016A (en) Carbon dioxide capturing, liquefying and recycling device and method
CN205536889U (en) Energy -saving low temperature air separation equipment of making nitrogen
CN112229143A (en) A device and method for producing oxygen and nitrogen by separating air by cryogenic rectification
CN112556313A (en) Heat supply and air separation system utilizing high-temperature and high-pressure steam and application method thereof
CN108007068B (en) Heat integration rectification air separation system for LNG cold energy utilization
CN110487023A (en) A method of liquid nitrogen is produced using LNG cold energy
CN213578367U (en) Device for producing oxygen and nitrogen by separating air through cryogenic rectification
WO2019127180A1 (en) Cryogenic rectification process-based method for producing air product, and air separation system
CN108036585B (en) Heat pump air separation system for LNG cold energy utilization
CN210267885U (en) Air separation equipment capable of producing liquid nitrogen
RU2699911C1 (en) Plant for producing lng
CN207751221U (en) A kind of heat pump air-seperation system of LNG cold energy uses

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant