CN114111216A - Device and method for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration - Google Patents

Device and method for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration Download PDF

Info

Publication number
CN114111216A
CN114111216A CN202111442053.5A CN202111442053A CN114111216A CN 114111216 A CN114111216 A CN 114111216A CN 202111442053 A CN202111442053 A CN 202111442053A CN 114111216 A CN114111216 A CN 114111216A
Authority
CN
China
Prior art keywords
nitrogen
channel
gas
methane
lng
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.)
Granted
Application number
CN202111442053.5A
Other languages
Chinese (zh)
Other versions
CN114111216B (en
Inventor
马忠
朱磊
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.)
Chengdu Shenleng Liquefaction Plant Co ltd
Original Assignee
Chengdu Shenleng Liquefaction Plant 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 Chengdu Shenleng Liquefaction Plant Co ltd filed Critical Chengdu Shenleng Liquefaction Plant Co ltd
Priority to CN202111442053.5A priority Critical patent/CN114111216B/en
Publication of CN114111216A publication Critical patent/CN114111216A/en
Application granted granted Critical
Publication of CN114111216B publication Critical patent/CN114111216B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0204Processes 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 characterised by the feed stream
    • F25J3/0219Refinery gas, cracking gas, coke oven gas, gaseous mixtures containing aliphatic unsaturated CnHm or gaseous mixtures of undefined nature
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0228Processes 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 characterised by the separated product stream
    • F25J3/0233Processes 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 characterised by the separated product stream separation of CnHm with 1 carbon atom or more
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0204Processes 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 characterised by the feed stream
    • F25J3/0209Natural gas or substitute natural gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0204Processes 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 characterised by the feed stream
    • F25J3/0223H2/CO mixtures, i.e. synthesis gas; Water gas or shifted synthesis gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0228Processes 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 characterised by the separated product stream
    • F25J3/0252Processes 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 characterised by the separated product stream separation of hydrogen
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02Processes 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
    • F25J3/0228Processes 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 characterised by the separated product stream
    • F25J3/0257Processes 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 characterised by the separated product stream separation of nitrogen
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J5/00Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2200/00Processes or apparatus using separation by rectification
    • F25J2200/02Processes or apparatus using separation by rectification in a single pressure main column system
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2200/00Processes or apparatus using separation by rectification
    • F25J2200/74Refluxing the column with at least a part of the partially condensed overhead gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00Processes characterised by the type or other details of the feed stream
    • F25J2210/12Refinery or petrochemical off-gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00Processes characterised by the type or other details of the feed stream
    • F25J2210/14Coke-ovens gas
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2215/00Processes characterised by the type or other details of the product stream
    • F25J2215/04Recovery of liquid products
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00Refrigeration techniques used
    • F25J2270/12External refrigeration with liquid vaporising loop
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00Refrigeration techniques used
    • F25J2270/14External refrigeration with work-producing gas expansion loop
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00Refrigeration techniques used
    • F25J2270/42Quasi-closed internal or closed external nitrogen refrigeration cycle
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/34Details about subcooling of liquids

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)

Abstract

The invention discloses a device and a method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration, which solve the technical problems that a natural gas liquefaction system in the prior art is complex to operate and maintain and has more requirements on the types of refrigerants. The system comprises a main heat exchanger (2), a precooling evaporator (3), an LNG rectifying tower reboiler (4), an LNG rectifying tower (5), a reflux tank (6), an LNG rectifying tower condenser (7), a nitrogen expansion refrigeration unit, an ice machine compression cooling unit and a control device; the nitrogen expansion refrigeration unit comprises a nitrogen compressor (8), a nitrogen compressor cooler (9), a turbo-charged expander cooler (10) and a turbo-charged expander (11); the ice machine compression cooling unit comprises an ice machine compressor (12) and an ice machine compressor cooler (13); and the main heat exchanger (2) is connected with a methane-rich gas inlet pipe (1). The invention has low operation difficulty, low manufacturing cost, lower energy consumption and high methane recovery efficiency.

Description

Device and method for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration
Technical Field
The invention relates to the field of natural gas liquefaction, in particular to a device for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration.
Background
The methane-rich gas comprises chemical synthesis tail gas of natural gas, coal bed gas, coke oven gas, methanol purge gas and synthetic ammonia purge gas, and gasification products of natural hydrate, and the main components of the methane-rich gas are methane, hydrogen, nitrogen, carbon monoxide and the like. The methane-rich gas is usually used for power generation, industrial fuel and the like, and because the fuel heat value is low and the combustion effect is not good, the discharged flue gas is difficult to reach the environmental protection standard, and the value is not fully applied. Therefore, the search for new methane-rich gas utilization paths is a problem faced by many enterprises. According to the difference of respective physical properties of different components in the methane-rich gas, the different components can be separated and purified by adopting low-temperature liquefaction and rectification separation technologies, so that the liquefied natural gas with high purity and high value is obtained. The liquefied natural gas is the third major energy source after coal and petroleum, can reduce the discharge amount of carbon dioxide compared with fuel and fire coal, can effectively improve the atmospheric environment, is convenient to transport and store, and has good market prospect, so that the problem of utilization of methane-rich gas is solved, and obvious environmental benefits and economic benefits can be generated.
The current natural gas liquefaction process mainly comprises the following steps: a cascade liquefaction process, a mixed refrigerant liquefaction process and a liquefaction process with an expander.
The cascade liquefaction process equipment has low energy consumption, the refrigerant is pure substance, the technology is mature, the operation is stable, but the whole system has complex processes, more static and dynamic equipment and complex system operation and maintenance due to the need of a plurality of independent refrigeration cycle systems.
The mixed refrigerant cycle is evolved from a cascade refrigeration cycle system, and the main principle is to mix a mixed refrigerant (the mixture comprises hydrocarbon mixtures such as C1-C5, N2 and the like) to make the Q-T curve of the mixed refrigerant approximately consistent with that of raw natural gas. Because the mixture is used as the refrigerating working medium, only 1 compressor is needed, the flow is simplified, and the manufacturing cost can be reduced. However, it is difficult to provide the required cooling capacity according to the Q-T cooling curve in the whole liquefaction process (from normal temperature to-162 ℃), and at most, only a part or a part of the Q-T curve can be close to the raw natural gas, so that the efficiency of the method is lower than that of a cascade refrigeration cycle, and the lowest refrigeration temperature is limited, which has a certain influence on the methane recovery rate of the raw gas.
The expansion machine refrigeration cycle is characterized in that high-pressure refrigerant is used for conducting adiabatic expansion through a turbine expansion machine to achieve the liquefaction of natural gas through the Kraud cycle refrigeration. The gas can also output energy while expanding and cooling in the expander, and can be used for driving a compressor in the process. Compared with the cascade refrigeration cycle and mixed refrigerant refrigeration cycle processes, the nitrogen expansion cycle process is very simple and compact, the manufacturing cost is low, a full-load product can be obtained after the hot start for several hours, the operation is flexible, the adaptability is strong, the operation and the control are easy, the safety is good, and the fire or explosion danger cannot be caused when the air is discharged. The refrigerant adopts single-component gas, thus eliminating the trouble of separating and storing the refrigerant like the mixed refrigerant refrigeration cycle process, avoiding the safety problem caused by the trouble and simplifying and compacting the liquefaction process.
As described above, the first two liquefaction processes have more requirements for the types of refrigerants, and are suitable for the base load type items with large liquefaction amount in places where refrigerants are easy to obtain. For some liquefaction plants with lower methane content and remote locations, where the refrigerant is not readily available, further optimization and adjustment of the liquefaction process is required.
Disclosure of Invention
The invention aims to provide a device and a method for extracting liquid methane from a methane-rich gas by nitrogen expansion refrigeration, so as to solve the technical problems that a natural gas liquefaction system in the prior art is complex to operate and maintain and has more requirements on the types of refrigerants.
In order to achieve the purpose, the invention provides the following technical scheme:
the invention provides a device for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration, which is characterized by comprising a main heat exchanger, a precooling evaporator, an LNG rectifying tower reboiler, an LNG rectifying tower, a reflux tank, an LNG rectifying tower condenser, a nitrogen expansion refrigeration unit, an ice machine compression cooling unit and a control device, wherein the main heat exchanger is connected with the precooling evaporator through the main heat exchanger; wherein the content of the first and second substances,
the nitrogen expansion refrigeration unit comprises a nitrogen compressor, a nitrogen compressor cooler, a turbo-charged expansion machine cooler and a turbo-charged expansion machine;
the ice machine compression cooling unit comprises an ice machine compressor and an ice machine compressor cooler;
the main heat exchanger is connected with a methane-rich gas inlet pipe;
a methane-rich gas channel I, a nitrogen-rich hydrogen tail gas channel I, a backflow low-pressure nitrogen channel I, a methane-rich gas channel II, a nitrogen channel III, an LNG channel and a nitrogen channel V are arranged in the main heat exchanger;
a precooling gas channel, a methane-rich gas channel III and a nitrogen channel IV are arranged in the precooling evaporator;
a nitrogen-rich hydrogen tail gas channel II and a backflow nitrogen channel II are arranged in the LNG rectifying tower condenser;
the methane-rich gas channel I, the methane-rich gas channel III and the methane-rich gas channel II are connected in sequence; the outlet end of the methane-rich gas channel II is connected with the feed inlet at the middle upper part of the LNG rectifying tower; the inlet end of the LNG rectifying tower condenser is connected with the gas phase outlet end at the top of the LNG rectifying tower;
the inlet end of the reflux tank is connected with the outlet end of the LNG rectifying tower condenser; the gas phase outlet end of the reflux tank is connected with the inlet end of a nitrogen-rich hydrogen tail gas channel I, and the outlet end of the nitrogen-rich hydrogen tail gas channel I is connected with a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid phase outlet end of the reflux tank is connected with the feed inlet at the top of the LNG rectifying tower;
a liquid phase outlet at the bottom of the LNG rectifying tower is connected with an inlet end of an LNG channel, and an outlet end of the LNG channel is connected with an LNG storage tank through an LNG pipeline;
the nitrogen expansion refrigeration unit provides nitrogen precooling expansion refrigeration circulation, and in the nitrogen expansion refrigeration circulation, along the airflow direction of nitrogen, the backflow low-pressure nitrogen channel I, the nitrogen compressor cooler, the turbo-charged expander cooler, the nitrogen channel I, the nitrogen channel IV, the nitrogen channel II, a hot side channel of an LNG rectifying tower reboiler and the nitrogen channel III are sequentially connected; the outlet end of the nitrogen channel III is provided with two gas paths, wherein one gas path comprises a turbo-charged expansion machine and a backflow low-pressure nitrogen channel I which are sequentially connected along the gas flow direction of nitrogen, and the backflow low-pressure nitrogen channel I enters a backflow low-pressure nitrogen channel I A3 from an inlet A3-1; the other gas path comprises a nitrogen channel V, a backflow nitrogen channel II and a backflow low-pressure nitrogen channel I which are sequentially connected along the gas flow direction of the nitrogen, and the backflow low-pressure nitrogen channel I enters a backflow low-pressure nitrogen channel I A3 from an inlet A3-2;
the ice machine compression cooling unit provides an ice machine compression cooling cycle, and in the ice machine compression cooling cycle, along the flowing direction of the organic working medium gas, the ice machine compressor cooler and the pre-cooling gas channel are sequentially connected;
the main heat exchanger, the precooling evaporator, the LNG rectifying tower reboiler, the LNG rectifying tower, the reflux tank, the LNG rectifying tower condenser, the nitrogen compressor, the turbo-charging expander and the ice machine compressor are respectively and electrically connected with the control device.
Further, the main heat exchanger, the precooling evaporator, the LNG rectifying tower condenser and the LNG rectifying tower reboiler are plate-fin heat exchangers, wound-tube heat exchangers or shell-and-tube heat exchangers.
Further, the LNG rectifying tower is a packed tower or a plate tower.
Furthermore, a bypass adjusting valve a is arranged between a hot side inlet and an outlet pipeline of the LNG rectifying tower reboiler; a regulating valve b for regulating the pressure of the methane-rich gas is arranged on a pipeline between the outlet end of the methane-rich gas channel II and the feed inlet at the middle upper part of the LNG rectifying tower;
the pipeline (LNG pipeline) at the outlet end of the LNG channel and the inlet end of the LNG storage tank is provided with an adjusting valve c;
a liquid level digital controller for monitoring the height of the kettle liquid is arranged on the LNG rectifying tower;
a temperature digital controller a for monitoring the gas phase temperature is arranged at the bottom of the LNG rectifying tower;
the reflux tank is provided with a pressure digital controller a for monitoring the pressure in the reflux tank;
the inlet end of the backflow tank is provided with a temperature digital controller b for monitoring the temperature of gas entering the backflow tank;
a pipeline at the inlet end of the backflow nitrogen channel II is provided with an adjusting valve d for adjusting the gas pressure;
a regulating valve f for regulating gas pressure is arranged between the pipeline at the outlet end of the cooler of the ice machine compressor and the pipeline at the inlet end of the pre-cooling evaporator;
a pressure digital controller b is arranged between the outlet end of the precooling evaporator and the inlet end pipeline of the ice machine compressor;
the nitrogen-rich hydrogen tail gas discharge pipeline is provided with a regulating valve e for regulating gas pressure;
the regulating valve a, the regulating valve b, the regulating valve c, the liquid level digital controller, the temperature digital controller a, the pressure digital controller a, the temperature digital controller b, the regulating valve d, the regulating valve f, the pressure digital controller b and the regulating valve e are respectively and electrically connected with the control device.
The invention provides a method for extracting liquid methane from methane-rich gas by adopting nitrogen expansion refrigeration, wherein the whole process of extracting the liquid methane provides cold energy through a nitrogen precooling expansion refrigeration cycle and an ice machine compression cooling cycle, and the specific extraction process comprises the following steps:
s1, feeding the purified and pressurized methane-rich gas (mainly containing methane, ethane, nitrogen and hydrogen) into a methane-rich gas channel I of a main heat exchanger from a gas inlet pipe, pre-cooling to-10 to-20 ℃, then feeding into a methane-rich gas channel III of a pre-cooling evaporator, cooling to-20 to-30 ℃, returning into a methane-rich gas channel II of the main heat exchanger, continuously cooling to-155 to-162 ℃, then reducing the pressure to 1.0MpaG through an adjusting valve b, and then feeding into an inlet end of an LNG rectifying tower for rectification and separation;
s2, allowing low-temperature gas with the temperature of-162 to-168 ℃ and the pressure of 0.8MpaG at the outlet end at the top of the LNG rectifying tower to enter a nitrogen-rich hydrogen tail gas channel II of a condenser of the LNG rectifying tower, cooling to-165 to-175 ℃, then allowing the low-temperature gas to enter a reflux tank for gas-liquid separation, returning low-temperature liquid at the bottom of the reflux tank to the inlet end of the LNG rectifying tower from a liquid phase outlet of the reflux tank, allowing the low-temperature gas at the top of the reflux tank to enter a nitrogen-rich hydrogen tail gas channel I of a main heat exchanger from a gas phase outlet of the reflux tank for heat exchange, heating to 20-35 ℃, and then discharging from a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid LNG with the temperature of-120 to-137 ℃ flowing out from the outlet end at the bottom of the LNG rectifying tower is sent into an LNG channel of the main heat exchanger to be continuously subcooled to-155 to-162 ℃, and then is sent into an LNG storage tank after being decompressed by a pressure regulating valve c.
Further, the process of the nitrogen precooling expansion refrigeration cycle comprises the following steps:
reheating low-pressure nitrogen of 0.1-0.5 MpaG through a return low-pressure nitrogen channel I of the main heat exchanger to 10-35 ℃, and then entering a nitrogen compressor to pressurize to 2.0-3.0 MPaG;
cooling the mixture to 25-45 ℃ in a nitrogen compressor cooler, and then sending the cooled mixture to a supercharging end of a turbocharging expansion machine for supercharging to 3.5-4.7 MpaG;
the supercharged gas enters a cooler of a turbo supercharged expansion machine to be cooled to 25-45 ℃ and then enters a nitrogen channel I of the main heat exchanger to be pre-cooled to-10 to-20 ℃;
then sending the nitrogen to a nitrogen channel IV of a precooling evaporator to continue cooling to-20 to-30 ℃, returning the low-temperature nitrogen to a nitrogen channel II of a main heat exchanger to be cooled to-110 to-120 ℃ and then entering a hot side channel of a reboiler of the LNG rectifying tower to be cooled to-125 to-135 ℃;
after the low-temperature nitrogen returns to the nitrogen channel III of the main heat exchanger and is reheated to-75 to-90 ℃, one path of gas enters the expansion end of the turbo-charged expansion machine, the temperature of the expanded nitrogen is reduced to-155 to-165 ℃, the pressure of the expanded nitrogen is reduced to 0.1 to 0.5MpaG, and then the expanded nitrogen enters the return low-pressure nitrogen channel I of the main heat exchanger from the A3-1 interface of the return low-pressure nitrogen channel I; and the other path of gas returns to the nitrogen channel V of the main heat exchanger to be continuously cooled to-155 to-163 ℃ and then is discharged out of the main heat exchanger, is subjected to pressure reduction by a pressure regulating valve to reach 0.1 to 0.5MpaG, enters the reflux nitrogen channel II of the LNG rectifying tower condenser to be reheated to-175 to-180 ℃, returns to the reflux low-pressure nitrogen channel from the A3-2 interface of the reflux low-pressure nitrogen channel I to be reheated to-155 to-162 ℃, and then enters the inlet of the nitrogen compressor after being reheated to 10 to 35 ℃ together with the low-pressure nitrogen from the A3-1 interface of the reflux low-pressure nitrogen channel I to complete nitrogen circulation.
Further, the process of the compression cooling cycle of the ice machine is as follows: the circulating low-pressure organic working medium gas flows out from the outlet of the precooling gas channel, enters the compressor of the ice machine for pressurization, flows out, enters the cooler of the compressor of the ice machine for cooling to 25-45 ℃, is subjected to pressure reduction and temperature reduction by the regulating valve f to-25-32 ℃, enters the precooling gas channel (B1) for heat exchange and temperature rise to-30 ℃, and enters the compressor of the ice machine to finish closed circulation.
Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:
(1) according to the device and the method for extracting liquid methane from the methane-rich gas through nitrogen expansion refrigeration, provided by the invention, the nitrogen refrigeration cycle and the ice machine precooling cycle are adopted in the process, only the nitrogen compressor, the nitrogen expander and the ice machine are needed, and compared with mixed refrigerant refrigeration, the device and the method are simple in process, small in operation difficulty and strong in universality.
(2) According to the device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration mode, the precooling part adopts an ice machine system for precooling, the technology is mature, the supply period of a standard machine type is short, and the failure rate of the system is low.
(3) The device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration method adopt the single-stage nitrogen expansion and throttling refrigeration technology, have low refrigeration temperature and high methane recovery rate, and the refrigeration working medium is environment-friendly and easy to popularize.
(4) The device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration method provided by the invention adopt the turbocharging technology, thereby not only obtaining high-quality low-temperature cold quantity, but also recovering the expansion work.
Drawings
Fig. 1 is a schematic structural diagram of an embodiment of the present invention.
In the figure: 1. an air inlet pipe; 2. a primary heat exchanger; 3. a pre-cooling evaporator; 4. an LNG rectifying tower reboiler; 5. an LNG rectification column; 6. a reflux tank; 7. a condenser of the LNG rectifying tower; 8. a nitrogen compressor; 9. a nitrogen compressor cooler; 10. a turbo expander cooler; 11. a turbo-charged expander; 12. an ice machine compressor; 13. an ice machine compressor cooler; 14. a pressure digital controller; 15. a liquid level digital controller; 16. adjusting valve b; 17. adjusting valve c; 18. a temperature digital controller; 19. adjusting a valve d; 20. adjusting the valve f; 21. a pressure digital controller; 22. adjusting a valve e; 23. adjusting a valve a; 24. a temperature digital controller; a1, a methane-rich gas channel I, A2, a nitrogen-rich hydrogen tail gas channel I, A3, a reflux low-pressure nitrogen channel I, A4, a nitrogen channel I, A5, a methane-rich gas channel II, A6, a nitrogen channel II, A7, nitrogen channels III and A8, an LNG channel, A9 and a nitrogen channel V; b1, a precooling gas channel, B2, methane-rich gas channels III and B3 and a nitrogen channel IV; c1, nitrogen-rich hydrogen tail gas channel II; c2 and a backflow nitrogen channel II.
Detailed Description
Example 1:
the invention provides a device for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration, which comprises a main heat exchanger 2, a precooling evaporator 3, an LNG rectifying tower reboiler 4, an LNG rectifying tower 5, a reflux tank 6, an LNG rectifying tower condenser 7, a nitrogen expansion refrigeration unit, an ice machine compression cooling unit and a control device, wherein the main heat exchanger is connected with the precooling evaporator; wherein the content of the first and second substances,
the nitrogen expansion refrigeration unit comprises a nitrogen compressor 8, a nitrogen compressor cooler 9, a turbo-charged expander cooler 10 and a turbo-charged expander 11;
the ice machine compression cooling unit comprises an ice machine compressor 12 and an ice machine compressor cooler 13;
the main heat exchanger 2 is connected with a methane-rich gas inlet pipe 1;
the main heat exchanger 2 is internally provided with a methane-rich gas channel IA1, a nitrogen-rich hydrogen tail gas channel IA2, a reflux low-pressure nitrogen channel IA3, a nitrogen channel IA4, a methane-rich gas channel IIA5, a nitrogen channel IIA6, a nitrogen channel IIIA7, an LNG channel A8 and a nitrogen channel V A9;
a pre-cooling air channel B1, a methane-rich gas channel IIIB2 and a nitrogen channel IVB3 are arranged in the pre-cooling evaporator 3;
a nitrogen-rich hydrogen tail gas channel IIC1 and a reflux nitrogen channel IIC2 are arranged in the LNG rectifying tower condenser 3;
the methane-rich gas passage IA1, the methane-rich gas passage IIIB2 and the methane-rich gas passage IIA5 are connected in sequence; the outlet end of the methane-rich gas channel IIA5 is connected with a feed inlet 5-B at the middle upper part of the LNG rectifying tower 5; the inlet end of the LNG rectifying tower condenser 7 is connected with a gas phase outlet end 5-A at the top of the LNG rectifying tower 5;
the inlet end 6-A of the reflux tank 6 is connected with the outlet end of the LNG rectifying tower condenser 7; the gas phase outlet end 6-C of the reflux tank 6 is connected with the inlet end of a nitrogen-rich hydrogen tail gas channel IA2, and the outlet end of the nitrogen-rich hydrogen tail gas channel IA2 is connected with a nitrogen-rich hydrogen tail gas discharge pipeline; a liquid phase outlet end 6-B of the reflux tank 6 is connected with a feed inlet 5-D at the top of the LNG rectifying tower 5;
a liquid phase outlet 5-C at the bottom of the LNG rectifying tower 5 is connected with the inlet end of an LNG channel A8, and the outlet end of the LNG channel A8 is connected with an LNG storage tank through an LNG pipeline;
the nitrogen expansion refrigeration unit provides a nitrogen pre-cooling expansion refrigeration cycle, and in the nitrogen expansion refrigeration cycle, along the gas flow direction of nitrogen, the reflux low-pressure nitrogen channel IA3, the nitrogen compressor 8, the nitrogen compressor cooler 9, the turbo-charged expander 11, the turbo-charged expander cooler 10, the nitrogen channel IA4, the nitrogen channel IVB3, the nitrogen channel IIA6, a hot side channel of the LNG rectifying tower reboiler 4 and the nitrogen channel IIIA7 are sequentially connected; the outlet end of the nitrogen channel IIIA7 is provided with two gas paths, wherein one gas path comprises a turbo-charging expander 11 and a backflow low-pressure nitrogen channel IA3 which are sequentially connected along the gas flow direction of nitrogen and enter a backflow low-pressure nitrogen channel I A3 from an inlet A3-1; the other gas path comprises a nitrogen channel V A9, a backflow nitrogen channel IIC2 and a backflow low-pressure nitrogen channel IA3 which are sequentially connected along the flow direction of nitrogen and enter a backflow low-pressure nitrogen channel I A3 from an inlet A3-2;
the ice machine compression cooling unit provides an ice machine compression cooling cycle, and in the ice machine compression cooling cycle, along the flowing direction of the organic working medium gas, the ice machine compressor 12, the ice machine compressor cooler 13 and the pre-cooling gas channel B1 are sequentially connected;
the main heat exchanger 2, the precooling evaporator 3, the LNG rectifying tower reboiler 4, the LNG rectifying tower 5, the reflux tank 6, the LNG rectifying tower condenser 7, the nitrogen compressor 8, the turbo-charging expander 11 and the ice machine compressor 12 are respectively and electrically connected with the control device.
According to the device and the method for extracting liquid methane from the methane-rich gas through nitrogen expansion refrigeration, provided by the invention, the nitrogen refrigeration cycle and the ice machine precooling cycle are adopted in the process, only the nitrogen compressor, the nitrogen expander and the ice machine are needed, and compared with mixed refrigerant refrigeration, the device and the method have the advantages of simple flow, small operation difficulty and strong universality; according to the device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration mode, the precooling part adopts an ice machine system for precooling, the technology is mature, the supply period of a standard machine type is short, and the failure rate of the system is low; the device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration mode adopt the single-stage nitrogen expansion and throttling refrigeration technology, have low refrigeration temperature and high methane recovery rate, and the refrigeration working medium is environment-friendly and easy to popularize; the device and the method for extracting liquid methane from the methane-rich gas by using the nitrogen precooling expansion refrigeration method provided by the invention adopt the turbocharging technology, thereby not only obtaining high-quality low-temperature cold quantity, but also recovering the expansion work.
As an alternative embodiment, the main heat exchanger 2, the precooling evaporator 3, the LNG rectification column condenser 7 and the LNG rectification column reboiler 4 are plate-fin heat exchangers, wound-tube heat exchangers or shell-and-tube heat exchangers.
As an alternative embodiment, the LNG rectification column 5 is a packed column or a plate column.
As an alternative embodiment, a bypass regulating valve a23 is arranged between the inlet and the outlet of the reboiler 4 at the hot side of the LNG rectification column; a regulating valve B16 for regulating the pressure of the methane-rich gas is arranged on a pipeline between the outlet end of the methane-rich gas channel IIA5 and a feeding hole 5-B at the middle upper part of the LNG rectifying tower 5;
an adjusting valve c17 is arranged on a pipeline LNG pipeline between the outlet end of the LNG channel A8 and the inlet end of the LNG storage tank;
a liquid level digital controller 15 for monitoring the height of the kettle liquid is arranged on the LNG rectifying tower 5;
a temperature digital controller a24 for monitoring the gas phase temperature is arranged at the bottom of the LNG rectifying tower 5;
the reflux tank 6 is provided with a pressure digital controller a14 for monitoring the pressure in the reflux tank 6;
the inlet end 6-A of the reflux tank 6 is provided with a temperature digital controller b18 for monitoring the temperature of the gas entering the reflux tank 6;
a pipeline at the inlet end of the backflow nitrogen channel IIC2 is provided with a regulating valve d19 for regulating the gas pressure;
a regulating valve f20 for regulating gas pressure is arranged between the outlet end of the ice machine compressor cooler 13 and the inlet end pipeline of the pre-cooling evaporator 3;
a pressure digital controller b21 is arranged between the outlet end of the pre-cooling evaporator 3 and the inlet end pipeline of the ice machine compressor 12;
a regulating valve e22 for regulating the gas pressure is arranged on the nitrogen-rich hydrogen tail gas discharge pipeline;
the regulating valve a23, the regulating valve b16, the regulating valve c17, the liquid level digital controller 15, the temperature digital controller a24, the pressure digital controller a14, the temperature digital controller b18, the regulating valve d19, the regulating valve f20, the pressure digital controller b21 and the regulating valve e22 are respectively electrically connected with a control device.
Example 2:
the device for extracting liquid methane from methane-rich gas by using nitrogen expansion refrigeration in embodiment 1 is used for extracting liquid methane from methane-rich gas, and the whole process of extracting liquid methane provides cold energy through nitrogen precooling expansion refrigeration cycle and ice machine compression cooling cycle, and the specific extraction process comprises the following steps:
s1, the purified and pressurized methane-rich gas mainly contains methane, ethane, nitrogen and hydrogen, enters a methane-rich gas channel IA1 of a main heat exchanger 2 from a gas inlet pipe 1, is pre-cooled to-15 ℃, then enters a methane-rich gas channel IIIB2 of a pre-cooling evaporator 3, is cooled to-25 ℃, returns to a methane-rich gas channel IIA5 of the main heat exchanger 2, is continuously cooled to-158 ℃, is decompressed to 1.0MpaG through a regulating valve B, and is sent to an inlet end 5-B of an LNG rectifying tower 5 for rectification and separation;
s2, the low-temperature gas with the temperature of-165 ℃ at the outlet end 5-A at the top of the LNG rectifying tower 5 and the pressure of 0.8MpaG enters a nitrogen-rich hydrogen tail gas channel IIC1 of an LNG rectifying tower condenser 7, is cooled to-170 ℃, then enters a reflux tank 6 for gas-liquid separation, the low-temperature liquid at the bottom of the reflux tank 6 returns to the inlet end 5-D of the LNG rectifying tower 5 from a liquid phase outlet 6-B of the reflux tank 6, and the low-temperature gas at the top of the reflux tank 6 enters a nitrogen-rich hydrogen tail gas channel IA2 of the main heat exchanger 2 from a gas phase outlet 6-C of the reflux tank for heat exchange and temperature rise to 30 ℃ and then is discharged from a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid LNG with the outflow temperature of minus 130 ℃ at the outlet end 5-C at the bottom of the LNG rectifying tower 5 is sent into an LNG channel A8 of the main heat exchanger 2 to be continuously subcooled to minus 157 ℃, and then is sent into an LNG storage tank after being decompressed by a pressure regulating valve C.
The process of the nitrogen precooling expansion refrigeration cycle is as follows:
the low-pressure nitrogen with the pressure of 0.3MpaG is reheated by a return low-pressure nitrogen channel IA3 of the main heat exchanger 2, heated to 30 ℃, enters a nitrogen compressor 8 and pressurized to 2.5 MPaG;
then the gas enters a nitrogen compressor cooler 9 to be cooled to 27 ℃, and then is sent to a supercharging end of a turbine supercharging expansion machine 11 to be supercharged to 4 MpaG;
the pressurized gas enters a turbine pressurizing expansion machine cooler 10 to be cooled to 25 ℃, and then enters a nitrogen channel IA4 of the main heat exchanger 2 to be pre-cooled to-15 ℃;
then sending the nitrogen to a nitrogen channel IVB3 of the precooling evaporator 3 to continue cooling to-25 ℃, returning the low-temperature nitrogen to a nitrogen channel IIA6 of the main heat exchanger 2 to be cooled to-115 ℃, then entering a hot side channel of an LNG rectifying tower reboiler 4, and cooling to-130 ℃;
after the low-temperature nitrogen returns to a nitrogen channel IIIA7 of the main heat exchanger 2 and is reheated to-85 ℃, one path of gas A7-1 enters an expansion end of a turbo-charging expander 11, the temperature of the expanded nitrogen is reduced to-161 ℃, the pressure of the expanded nitrogen is reduced to 0.33MpaG, and then the expanded nitrogen enters a return low-pressure nitrogen channel IA3 channel of the main heat exchanger 2 from an A3-1 interface of a return low-pressure nitrogen channel IA3 channel; and the other path of gas A7-2 returns to the nitrogen channel V of the main heat exchanger 2 again to be continuously cooled to-157 ℃ and then is discharged out of the main heat exchanger 2, the temperature is reduced to 0.3MpaG through a pressure regulating valve, the gas enters the reflux nitrogen channel IIC2 of the LNG rectifying tower condenser 7 to be reheated to-175 ℃, the gas returns to the reflux low-pressure nitrogen channel IA3 through the A3-2 interface of the reflux low-pressure nitrogen channel IA3 to be reheated to-157 ℃, the gas and the low-pressure nitrogen at the A3-1 interface of the reflux low-pressure nitrogen channel IA3 are reheated to 20 ℃ through the reflux low-pressure nitrogen channel IA3, and then the gas enters the inlet of the nitrogen compressor 8 to finish nitrogen circulation.
The process of the compression cooling cycle of the ice machine is as follows:
the circulating low-pressure organic working medium gas flows out from an outlet of the pre-cooling gas channel B1, enters an ice machine compressor 12 for pressurization, flows out, enters an ice machine compressor cooler 13 for cooling to 35 ℃, is subjected to pressure reduction and temperature reduction by an adjusting valve f20 to-28 ℃, enters a pre-cooling gas channel B1 for heat exchange and temperature rise to-30 ℃, enters the ice machine compressor 12, and completes closed circulation.
In this embodiment:
Figure BDA0003383707640000111
the methane-rich gas is separated and liquefied under the condition of gas inlet, the power of the nitrogen compressor 8 is 3420kW, and the power of the ice machine compressor 12 is 230 kW. From the above data, it can be seen that the yield of methane is 98.89%, and separation by liquefaction per Nm3The energy consumption of the LNG is 0.583kW/Nm3(LNG) which is 7% lower than the energy consumption of nitrogen expansion refrigeration without precooling.
Example 3:
the device for extracting liquid methane from methane-rich gas by using nitrogen expansion refrigeration in embodiment 1 is used for extracting liquid methane from methane-rich gas, and the whole process of extracting liquid methane provides cold energy through nitrogen precooling expansion refrigeration cycle and ice machine compression cooling cycle, and the specific extraction process comprises the following steps:
s1, the purified and pressurized methane-rich gas mainly contains methane, ethane, nitrogen and hydrogen, enters a methane-rich gas channel IA1 of a main heat exchanger 2 from a gas inlet pipe 1, is pre-cooled to-20 ℃, then enters a methane-rich gas channel IIIB2 of a pre-cooling evaporator 3, is cooled to-30 ℃, returns to a methane-rich gas channel IIA5 of the main heat exchanger 2, is continuously cooled to-162 ℃, is decompressed to 1.0MpaG by a regulating valve B, and is sent to an inlet end 5-B of an LNG rectifying tower 5 for rectification and separation;
s2, the low-temperature gas with the temperature of-162 ℃ at the outlet end 5-A at the top of the LNG rectifying tower 5 and the pressure of 0.75MpaG enters a nitrogen-rich hydrogen tail gas channel IIC1 of an LNG rectifying tower condenser 7, is cooled to-175 ℃, then enters a reflux tank 6 for gas-liquid separation, the low-temperature liquid at the bottom of the reflux tank 6 returns to the inlet end 5-D of the LNG rectifying tower 5 from a liquid phase outlet 6-B of the reflux tank 6, and the low-temperature gas at the top of the reflux tank 6 enters a nitrogen-rich hydrogen tail gas channel IA2 of the main heat exchanger 2 from a gas phase outlet 6-C of the reflux tank for heat exchange and temperature rise to 35 ℃ and then is discharged from a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid LNG with the outflow temperature of minus 137 ℃ at the outlet end 5-C at the bottom of the LNG rectifying tower 5 is sent into an LNG channel A8 of the main heat exchanger 2 to be continuously subcooled to minus 162 ℃, and then is sent into an LNG storage tank after being decompressed by a pressure regulating valve C.
The process of the nitrogen precooling expansion refrigeration cycle is as follows:
the low-pressure nitrogen with the pressure of 0.5MpaG is reheated and heated to 35 ℃ through a return low-pressure nitrogen channel IA3 of the main heat exchanger 2, and then enters a nitrogen compressor 8 to be pressurized to 3.0 MPaG;
then enters a nitrogen compressor cooler 9 to be cooled to 30 ℃ and then is sent to the supercharging end of a turbine supercharging expander 11 to be supercharged to 4.7 MpaG;
the pressurized gas enters a turbine pressurizing expansion machine cooler 10 to be cooled to 25 ℃, and then enters a nitrogen channel IA4 of the main heat exchanger 2 to be pre-cooled to-20 ℃;
then sending the cooled nitrogen to a nitrogen channel IVB3 of the precooling evaporator 3 to continue cooling to-30 ℃, returning the low-temperature nitrogen to a nitrogen channel IIA6 of the main heat exchanger 2 to be cooled to-120 ℃ again, and then entering a hot side channel of an LNG rectifying tower reboiler 4 to be cooled to-135 ℃;
after the low-temperature nitrogen returns to the nitrogen channel IIIA7 of the main heat exchanger 2 and is reheated to-90 ℃, one path of gas A7-1 enters the expansion end of the turbo-charged expander 11, the temperature of the expanded nitrogen is reduced to-160 ℃, the pressure of the expanded nitrogen is reduced to 0.53MpaG, and then the expanded nitrogen enters the return low-pressure nitrogen channel IA3 channel of the main heat exchanger 2 from the A3-1 interface of the return low-pressure nitrogen channel IA3 channel; and the other path of gas A7-2 returns to the nitrogen channel V of the main heat exchanger 2 again to be continuously cooled to-163 ℃ and then is discharged out of the main heat exchanger 2, the temperature is reduced to 0.5MpaG through a pressure regulating valve, the gas enters the reflux nitrogen channel IIC2 of the LNG rectifying tower condenser 7 to be reheated to-177 ℃, the gas returns to the reflux low-pressure nitrogen channel IA3 from the A3-2 interface of the reflux low-pressure nitrogen channel IA3 to be reheated to-162 ℃, the gas and the low-pressure nitrogen at the A3-1 interface of the reflux low-pressure nitrogen channel IA3 are reheated to 35 ℃ in the reflux low-pressure nitrogen channel IA3, and then the gas enters the inlet of the nitrogen compressor 8 to finish nitrogen circulation.
The process of the compression cooling cycle of the ice machine is as follows:
the circulating low-pressure organic working medium gas flows out from an outlet of the pre-cooling gas channel B1, enters an ice machine compressor 12 for pressurization, flows out, enters an ice machine compressor cooler 13 for cooling to 45 ℃, is subjected to pressure reduction and temperature reduction by an adjusting valve f20 to-32 ℃, enters a pre-cooling gas channel B1 for heat exchange and temperature rise to-30 ℃, enters the ice machine compressor 12, and completes closed circulation.
In this embodiment:
Figure BDA0003383707640000131
the methane-rich gas is separated and liquefied under the condition of gas inlet, the power of the nitrogen compressor 8 is 3400kW, and the power of the ice machine compressor 12 is 210 kW. From the above data, it can be seen that the yield of methane is 98.89%, and separation by liquefaction per Nm3The energy consumption of the LNG is 0.578 kW/Nm/h3(LNG), the energy consumption is 8% lower than that of nitrogen expansion refrigeration without precooling.
Example 4:
the device for extracting liquid methane from methane-rich gas by using nitrogen expansion refrigeration in embodiment 1 is used for extracting liquid methane from methane-rich gas, and the whole process of extracting liquid methane provides cold energy through nitrogen precooling expansion refrigeration cycle and ice machine compression cooling cycle, and the specific extraction process comprises the following steps:
s1, the purified and pressurized methane-rich gas mainly contains methane, ethane, nitrogen and hydrogen, enters a methane-rich gas channel IA1 of a main heat exchanger 2 from a gas inlet pipe 1, is pre-cooled to-10 ℃, then enters a methane-rich gas channel IIIB2 of a pre-cooling evaporator 3, is cooled to-20 ℃, returns to a methane-rich gas channel IIA5 of the main heat exchanger 2, is continuously cooled to-155 ℃, is decompressed to 1.0MpaG by a regulating valve B, and is sent to an inlet end 5-B of an LNG rectifying tower 5 for rectification and separation;
s2, the low-temperature gas with the temperature of-162 ℃ and the pressure of 0.8MpaG at the outlet end 5-A at the top of the LNG rectifying tower 5 enters a nitrogen-rich hydrogen tail gas channel IIC1 of an LNG rectifying tower condenser 7, is cooled to-165 ℃ and then enters a reflux tank 6 for gas-liquid separation, the low-temperature liquid at the bottom of the reflux tank 6 returns to the inlet end 5-D of the LNG rectifying tower 5 from a liquid phase outlet 6-B of the reflux tank 6, and the low-temperature gas at the top of the reflux tank 6 enters a nitrogen-rich hydrogen tail gas channel IA2 of the main heat exchanger 2 from a gas phase outlet 6-C of the reflux tank for heat exchange and temperature rise to 20 ℃ and then is discharged from a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid LNG with the outflow temperature of minus 120 ℃ at the outlet end 5-C at the bottom of the LNG rectifying tower 5 is sent into an LNG channel A8 of the main heat exchanger 2 to be continuously subcooled to minus 155 ℃, and then is sent into an LNG storage tank after being decompressed by a pressure regulating valve C.
The process of the nitrogen precooling expansion refrigeration cycle is as follows:
the low-pressure nitrogen with the pressure of 0.1MpaG is reheated and heated to 30 ℃ through a return low-pressure nitrogen channel IA3 of the main heat exchanger 2, and then enters a nitrogen compressor 8 to be pressurized to 2.0 MPaG;
then the mixed gas enters a nitrogen compressor cooler 9 to be cooled to 27 ℃, and then is sent to a supercharging end of a turbine supercharging expansion machine 11 to be supercharged to 3.5 MpaG;
the pressurized gas enters a turbine pressurizing expansion machine cooler 10 to be cooled to 25 ℃, and then enters a nitrogen channel IA4 of the main heat exchanger 2 to be pre-cooled to-10 ℃;
then sending the cooled nitrogen to a nitrogen channel IVB3 of a precooling evaporator 3 to continue cooling to-20 ℃, returning the low-temperature nitrogen to a nitrogen channel IIA6 of a main heat exchanger 2 to be cooled to-110 ℃, then entering a hot side channel of an LNG rectifying tower reboiler 4, and cooling to-125 ℃;
after the low-temperature nitrogen returns to the nitrogen channel IIIA7 of the main heat exchanger 2 and is reheated to-75 ℃, one path of gas A7-1 enters the expansion end of the turbo-charged expander 11, the temperature of the expanded nitrogen is reduced to-155 ℃, the pressure of the expanded nitrogen is reduced to 0.1MpaG, and then the expanded nitrogen enters the return low-pressure nitrogen channel IA3 channel of the main heat exchanger 2 from the A3-1 interface of the return low-pressure nitrogen channel IA3 channel; and the other path of gas A7-2 returns to the nitrogen channel V of the main heat exchanger 2 again to be continuously cooled to-155 ℃, is discharged out of the main heat exchanger 2, is subjected to pressure reduction by a pressure regulating valve to 0.1MpaG, enters the reflux nitrogen channel IIC2 of the LNG rectifying tower condenser 7 to be reheated to-175 ℃, returns to the reflux low-pressure nitrogen channel IA3 from the A3-2 interface of the reflux low-pressure nitrogen channel IA3 to be reheated to-155 ℃, is reheated to 10 ℃ together with the low-pressure nitrogen at the A3-1 interface of the reflux low-pressure nitrogen channel IA3 in the reflux low-pressure nitrogen channel IA3, and then enters the inlet of the nitrogen compressor 8 to finish nitrogen circulation.
The process of the compression cooling cycle of the ice machine is as follows:
the circulating low-pressure organic working medium gas flows out from an outlet of the pre-cooling gas channel B1, enters an ice machine compressor 12 for pressurization, flows out, enters an ice machine compressor cooler 13 for cooling to 25 ℃, is subjected to pressure reduction and temperature reduction by an adjusting valve f20 to-32 ℃, enters a pre-cooling gas channel B1 for heat exchange and temperature rise to-30 ℃, enters the ice machine compressor 12, and completes closed circulation.
In this embodiment:
Figure BDA0003383707640000151
the methane-rich gas is separated and liquefied under the condition of gas inlet, the power of the nitrogen compressor 8 is 3500kW, and the power of the ice machine compressor 12 is 240 kW. From the above data, it can be seen that the yield of methane is 98.89%, and separation by liquefaction per Nm3The energy consumption of the LNG is 0.598kW/Nm3(LNG) 5% lower energy consumption compared to nitrogen expansion refrigeration without precooling.

Claims (7)

1. A device for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration is characterized by comprising a main heat exchanger (2), a precooling evaporator (3), an LNG rectifying tower reboiler (4), an LNG rectifying tower (5), a reflux tank (6), an LNG rectifying tower condenser (7), a nitrogen expansion refrigeration unit, an ice machine compression cooling unit and a control device; wherein the content of the first and second substances,
the nitrogen expansion refrigeration unit comprises a nitrogen compressor (8), a nitrogen compressor cooler (9), a turbo-charged expander cooler (10) and a turbo-charged expander (11);
the ice machine compression cooling unit comprises an ice machine compressor (12) and an ice machine compressor cooler (13);
the main heat exchanger (2) is connected with a methane-rich gas inlet pipe (1);
a methane-rich gas channel I (A1), a nitrogen-rich hydrogen tail gas channel I (A2), a reflux low-pressure nitrogen channel I (A3), a nitrogen channel I (A4), a methane-rich gas channel II (A5), a nitrogen channel II (A6), a nitrogen channel III (A7), an LNG channel (A8) and a nitrogen channel V (A9) are arranged in the main heat exchanger (2);
a pre-cooling gas channel (B1), a methane-rich gas channel III (B2) and a nitrogen channel IV (B3) are arranged in the pre-cooling evaporator (3);
a nitrogen-rich hydrogen tail gas channel II (C1) and a reflux nitrogen channel II (C2) are arranged in the LNG rectifying tower condenser (3);
the methane-rich gas channel I (A1), the methane-rich gas channel III (B2) and the methane-rich gas channel II (A5) are connected in sequence; the outlet end of the methane-rich gas channel II (A5) is connected with the feed inlet at the middle upper part of the LNG rectifying tower (5); the inlet end of the LNG rectifying tower condenser (7) is connected with the gas phase outlet end at the top of the LNG rectifying tower (5);
the inlet end of the reflux tank (6) is connected with the outlet end of the LNG rectifying tower condenser (7); the gas phase outlet end of the reflux tank (6) is connected with the inlet end of a nitrogen-rich hydrogen tail gas channel I (A2), and the outlet end of the nitrogen-rich hydrogen tail gas channel I (A2) is connected with a nitrogen-rich hydrogen tail gas discharge pipeline; the liquid phase outlet end of the reflux tank (6) is connected with the feed inlet at the top of the LNG rectifying tower (5);
a liquid phase outlet at the bottom of the LNG rectifying tower (5) is connected with an inlet end of an LNG channel (A8), and an outlet end of the LNG channel (A8) is connected with an LNG storage tank through an LNG pipeline;
the nitrogen expansion refrigeration unit provides a nitrogen precooling expansion refrigeration cycle, and in the nitrogen expansion refrigeration cycle, along the gas flow direction of nitrogen, the reflux low-pressure nitrogen channel I (A3), the nitrogen compressor (8), the nitrogen compressor cooler (9), the turbo-charged expander (11), the turbo-charged expander cooler (10), the nitrogen channel I (A4), the nitrogen channel IV (B3), the nitrogen channel II (A6), a hot side channel of an LNG rectifying tower reboiler (4), and the nitrogen channel III (A7) are connected in sequence; the outlet end of the nitrogen channel III (A7) is provided with two gas paths, wherein one gas path comprises a turbo-charging expander (11) and a backflow low-pressure nitrogen channel I (A3) which are sequentially connected along the gas flow direction of nitrogen, and the backflow low-pressure nitrogen channel I (A3) enters the backflow low-pressure nitrogen channel I (A3) from an inlet A3-1; the other gas path comprises a nitrogen channel V (A9), a backflow nitrogen channel II (C2) and a backflow low-pressure nitrogen channel I (A3) which are sequentially connected along the gas flow direction of the nitrogen and enter the backflow low-pressure nitrogen channel I (A3) from an inlet A3-2;
the ice machine compression cooling unit provides an ice machine compression cooling cycle, and in the ice machine compression cooling cycle, along the flowing direction of the organic working medium gas, the ice machine compressor (12), the ice machine compressor cooler (13) and the pre-cooling gas channel (B1) are sequentially connected;
the main heat exchanger (2), the precooling evaporator (3), the LNG rectifying tower reboiler (4), the LNG rectifying tower (5), the reflux tank (6), the LNG rectifying tower condenser (7), the nitrogen compressor (8), the turbo-charged expander (11) and the ice machine compressor (12) are respectively and electrically connected with the control device.
2. The device for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration as claimed in claim 1, wherein the main heat exchanger (2), the precooling evaporator (3), the LNG rectification tower condenser (7) and the LNG rectification tower reboiler (4) are plate-fin heat exchangers, wound-tube heat exchangers or shell-and-tube heat exchangers.
3. The apparatus for liquid methane extraction from a methane-rich gas with nitrogen expansion refrigeration as claimed in claim 1, wherein the LNG rectification column (5) is a packed column or a plate column.
4. The device for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration as claimed in claim 1, wherein a bypass regulating valve a (23) is arranged between an inlet and an outlet of a hot side of the LNG rectifying tower reboiler (4); a regulating valve b (16) for regulating the pressure of the methane-rich gas is arranged on a pipeline between the outlet end of the methane-rich gas channel II (A5) and the feed inlet at the middle upper part of the LNG rectifying tower (5);
the pipeline between the outlet end of the LNG channel (A8) and the inlet end of the LNG storage tank is provided with a regulating valve c (17);
a liquid level digital controller (15) for monitoring the height of the kettle liquid is arranged on the LNG rectifying tower (5);
a temperature digital controller a (24) for monitoring the gas phase temperature is arranged at the bottom of the LNG rectifying tower (5);
a pressure digital controller a (14) for monitoring the pressure in the reflux tank (6) is arranged on the reflux tank (6);
the inlet end of the reflux tank (6) is provided with a temperature digital controller b (18) for monitoring the temperature of the gas entering the reflux tank (6);
a regulating valve d (19) for regulating the gas pressure is arranged on a pipeline at the inlet end of the reflux nitrogen channel II (C2);
a regulating valve f (20) for regulating gas pressure is arranged between the outlet end of the cooler (13) of the ice machine compressor and the inlet end pipeline of the precooling evaporator (3);
a pressure digital controller b (21) is arranged between the outlet end of the pre-cooling evaporator (3) and the inlet end pipeline of the ice machine compressor (12);
a regulating valve e (22) for regulating the gas pressure is arranged on the nitrogen-rich hydrogen tail gas discharge pipeline;
the regulating valve a (23), the regulating valve b (16), the regulating valve c (17), the liquid level digital controller (15), the temperature digital controller a (24), the pressure digital controller a (14), the temperature digital controller b (18), the regulating valve d (19), the regulating valve f (20), the pressure digital controller b (21) and the regulating valve e (22) are respectively and electrically connected with the control device.
5. A method for extracting liquid methane from methane-rich gas by using nitrogen expansion refrigeration as claimed in any one of claims 1-4, wherein the whole process of extracting the liquid methane provides refrigeration by a nitrogen precooling expansion refrigeration cycle and an ice machine compression cooling cycle, and the specific extraction process comprises the following steps:
s1, enabling the purified and pressurized methane-rich gas to enter a methane-rich gas channel I (A1) of a main heat exchanger (2) from an air inlet pipe (1), pre-cooling to-10 to-20 ℃, then entering a methane-rich gas channel III (B2) of a pre-cooling evaporator (3), cooling to-20 to-30 ℃, returning to a methane-rich gas channel II (A5) of the main heat exchanger (2), continuously cooling to-155 to-162 ℃, reducing the pressure to 1.0MpaG through an adjusting valve B, and then sending to the inlet end of an LNG rectifying tower (5) for rectification and separation;
s2, enabling low-temperature gas with the temperature of-162 to-168 ℃ and the pressure of 0.8MpaG at the outlet end at the top of the LNG rectifying tower (5) to enter a nitrogen-rich hydrogen tail gas channel II (C1) of a condenser (7) of the LNG rectifying tower to be cooled to-165 to-175 ℃, then enabling the low-temperature gas to enter a reflux tank (6) for gas-liquid separation, enabling low-temperature liquid at the bottom of the reflux tank (6) to return to the inlet end of the LNG rectifying tower (5) from a liquid phase outlet of the reflux tank (6), enabling the low-temperature gas at the top of the reflux tank (6) to enter a nitrogen-rich hydrogen tail gas channel I (A2) of a main heat exchanger (2) from a gas phase outlet 6-C of the reflux tank for heat exchange, heating to 20 to 35 ℃, and then enabling the low-temperature gas to be discharged from a nitrogen-rich hydrogen tail gas discharge pipeline; liquid LNG with the temperature of-120 to-137 ℃ flows out from the outlet end at the bottom of the LNG rectifying tower (5) and is sent into an LNG channel (A8) of the main heat exchanger (2) to be continuously subcooled to-155 to-162 ℃, and then is sent into an LNG storage tank after being decompressed by a pressure regulating valve c.
6. The method of claim 5, wherein the nitrogen pre-cooling expansion refrigeration cycle comprises:
reheating low-pressure nitrogen of 0.1-0.5 MpaG to 10-35 ℃ through a backflow low-pressure nitrogen channel I (A3) of the main heat exchanger (2), and then entering a nitrogen compressor (8) to pressurize to 2.0-3.0 MPaG;
then the mixed gas enters a nitrogen compressor cooler (9) to be cooled to 25-45 ℃ and then is sent to a supercharging end of a turbine supercharging expansion machine (11) to be supercharged to 3.5-4.7 MpaG;
the supercharged gas enters a turbo-supercharged expansion machine cooler (10) to be cooled to 25-45 ℃ and then enters a nitrogen channel I (A4) of the main heat exchanger (2) to be pre-cooled to-10 to-20 ℃;
then sending the nitrogen to a nitrogen channel IV (B3) of a precooling evaporator (3) for continuous cooling to-20 to-30 ℃, returning the low-temperature nitrogen to a nitrogen channel II (A6) of a main heat exchanger (2) for re-cooling to-110 to-120 ℃, then entering a hot side channel of a reboiler (4) of the LNG rectifying tower for cooling to-125 to-135 ℃;
after the low-temperature nitrogen returns to the nitrogen channel III (A7) of the main heat exchanger (2) and is reheated to-75 to-90 ℃, one path of gas enters the expansion end of the turbo-charged expansion machine (11), the temperature of the expanded nitrogen is reduced to-155 to-165 ℃, the pressure is reduced to 0.1 to 0.5MpaG, and then the expanded nitrogen enters the return low-pressure nitrogen channel I (A3) of the main heat exchanger (2) from the A3-1 interface of the return low-pressure nitrogen channel I (A3); and the other path of gas returns to the nitrogen channel V of the main heat exchanger (2) and is continuously cooled to-155 to-163 ℃ to be discharged out of the main heat exchanger (2), is reduced to 0.1 to 0.5MpaG by a pressure regulating valve, enters a return nitrogen channel II (C2) of an LNG rectifying tower condenser (7) and is reheated to-175 to-180 ℃, returns to the return low-pressure nitrogen channel I (A3) from an A3-2 interface of the return low-pressure nitrogen channel I (A3) and is reheated to-155 to-162 ℃, and then enters an inlet of a nitrogen compressor (8) together with the low-pressure nitrogen at an A3-1 interface of the return low-pressure nitrogen channel I (A3) after being reheated to 10 to 35 ℃ from an A3 channel of the return low-pressure nitrogen channel I (A3), so as to finish nitrogen circulation.
7. The method of nitrogen expansion refrigeration for liquid methane extraction from methane-rich gas as claimed in claim 5, wherein the process of the ice machine compression cooling cycle is: the circulating low-pressure organic working medium gas flows out from the outlet of the pre-cooling gas channel (B1), enters an ice machine compressor (12) for pressurization, flows out, enters an ice machine compressor cooler (13) for cooling to 25-45 ℃, is subjected to pressure reduction and temperature reduction by an adjusting valve f (20) to-25-32 ℃, enters the pre-cooling gas channel (B1) for heat exchange and temperature rise to-30 ℃, and enters the ice machine compressor (12) to complete closed circulation.
CN202111442053.5A 2021-11-30 2021-11-30 Device and method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration Active CN114111216B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111442053.5A CN114111216B (en) 2021-11-30 2021-11-30 Device and method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111442053.5A CN114111216B (en) 2021-11-30 2021-11-30 Device and method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration

Publications (2)

Publication Number Publication Date
CN114111216A true CN114111216A (en) 2022-03-01
CN114111216B CN114111216B (en) 2024-05-14

Family

ID=80368024

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111442053.5A Active CN114111216B (en) 2021-11-30 2021-11-30 Device and method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration

Country Status (1)

Country Link
CN (1) CN114111216B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102435044A (en) * 2011-12-13 2012-05-02 杭州中泰深冷技术股份有限公司 Cryogenic separating system for preparing liquefied natural gas with oven gas
CN104567276A (en) * 2014-12-30 2015-04-29 杭州凯德空分设备有限公司 Device and technological method for producing LNG (liquefied natural gas) by recycling ammonia tail gas
CN204693949U (en) * 2015-06-08 2015-10-07 成都深冷液化设备股份有限公司 A kind of separation high methane gas device with n-formyl sarcolysine alkane refrigerating function
CN105180595A (en) * 2015-09-16 2015-12-23 开封空分集团有限公司 System and method for preparing hydrogen rich gas and liquid methane
CN216868944U (en) * 2021-11-30 2022-07-01 四川蜀道装备科技股份有限公司 Device for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102435044A (en) * 2011-12-13 2012-05-02 杭州中泰深冷技术股份有限公司 Cryogenic separating system for preparing liquefied natural gas with oven gas
CN104567276A (en) * 2014-12-30 2015-04-29 杭州凯德空分设备有限公司 Device and technological method for producing LNG (liquefied natural gas) by recycling ammonia tail gas
CN204693949U (en) * 2015-06-08 2015-10-07 成都深冷液化设备股份有限公司 A kind of separation high methane gas device with n-formyl sarcolysine alkane refrigerating function
CN105180595A (en) * 2015-09-16 2015-12-23 开封空分集团有限公司 System and method for preparing hydrogen rich gas and liquid methane
CN216868944U (en) * 2021-11-30 2022-07-01 四川蜀道装备科技股份有限公司 Device for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration

Also Published As

Publication number Publication date
CN114111216B (en) 2024-05-14

Similar Documents

Publication Publication Date Title
CN101650112B (en) Combined synthesis gas separation and lng production method and system
WO2019071869A1 (en) Device and method using stepped cooling to recover ethane from natural gas
WO2013191948A1 (en) Natural gas liquefaction employing independent refrigerant path
MXPA04006946A (en) Self-refrigerated lng process.
US7225636B2 (en) Apparatus and methods for processing hydrocarbons to produce liquified natural gas
CN101893367A (en) Method for liquefying natural gas by using mixed coolant
CN103175381B (en) Process for preparing LNG (liquefied natural gas) by low-concentration coal bed gas oxygen-containing cryogenic liquefaction
CN113959176B (en) System and method for separating helium from liquefied natural gas flash gas
CN113865263B (en) Production system for extracting crude helium and co-producing liquefied natural gas by natural gas
CN216868944U (en) Device for extracting liquid methane from methane-rich gas through nitrogen expansion refrigeration
CN110762392A (en) Device for producing LNG (liquefied Natural gas) and CNG (compressed Natural gas) by separating methane in coal-to-synthesis gas through double refrigeration cycles
CN104807287A (en) Small natural gas liquefaction and refrigeration system and small natural gas liquefaction and refrigeration method
CN101709238B (en) Method for preparing liquefied natural gas by using coke-oven gas
CN114111217B (en) Device and method for preparing LNG and synthetic ammonia feed gas by liquid nitrogen washing
CN113862051B (en) Double refrigeration cycle methane washing synthetic gas cryogenic separation device and separation method
WO2020248328A1 (en) Three-cycle natural gas liquefaction apparatus and method suitable for ultra-large scale
CN103175380B (en) Device for preparing LNG (liquefied natural gas) by low-concentration coal bed gas oxygen-containing cryogenic liquefaction
CN103398545A (en) System for producing liquefied natural gas by multistage pressure throttling of feed gas
CN114111216B (en) Device and method for extracting liquid methane from methane-rich gas by nitrogen expansion refrigeration
CN217900304U (en) Device for recovering argon and methane from synthetic ammonia tail gas
CN114165987B (en) Liquid carbon dioxide production device and production method thereof
CN114777412A (en) Hydrogen liquefying plant with thermal siphon type hydrogen subcooler
CN110160315B (en) Liquid air separation device utilizing low-cost night electric power and production method
CN109210867B (en) System for retrieve methane in follow oxygen-bearing coal bed gas
CN110627609B (en) Ethane recovery method combining mixed refrigerant and propane auxiliary refrigeration

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
CB02 Change of applicant information

Country or region after: China

Address after: 611700 No. 569, tongshanqiao Road, north area of modern industrial port, Pidu District, Chengdu, Sichuan

Applicant after: Sichuan Shudao Equipment Technology Co.,Ltd.

Address before: 611700 No. 569, tongshanqiao Road, north area of modern industrial port, Pidu District, Chengdu, Sichuan

Applicant before: CHENGDU SHENLENG LIQUEFACTION PLANT Co.,Ltd.

Country or region before: China

CB02 Change of applicant information
GR01 Patent grant
GR01 Patent grant