CN201028930Y - Natural gas liquefaction device - Google Patents
Natural gas liquefaction device Download PDFInfo
- Publication number
- CN201028930Y CN201028930Y CN 200720124160 CN200720124160U CN201028930Y CN 201028930 Y CN201028930 Y CN 201028930Y CN 200720124160 CN200720124160 CN 200720124160 CN 200720124160 U CN200720124160 U CN 200720124160U CN 201028930 Y CN201028930 Y CN 201028930Y
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- Prior art keywords
- natural gas
- methane
- cooler
- liquid
- gas
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 455
- 239000003345 natural gas Substances 0.000 title claims abstract description 94
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims abstract description 212
- 239000007788 liquid Substances 0.000 claims abstract description 163
- 239000007789 gas Substances 0.000 claims abstract description 137
- 239000001294 propane Substances 0.000 claims abstract description 107
- 239000003949 liquefied natural gas Substances 0.000 claims abstract description 53
- 238000001704 evaporation Methods 0.000 claims abstract description 24
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 115
- 238000000926 separation method Methods 0.000 claims description 79
- 239000005977 Ethylene Substances 0.000 claims description 72
- 239000012530 fluid Substances 0.000 claims description 64
- 239000003595 mist Substances 0.000 claims description 43
- 238000001816 cooling Methods 0.000 claims description 23
- 230000008020 evaporation Effects 0.000 claims description 23
- 239000004215 Carbon black (E152) Substances 0.000 claims description 17
- 229930195733 hydrocarbon Natural products 0.000 claims description 17
- 150000002430 hydrocarbons Chemical class 0.000 claims description 17
- 238000002156 mixing Methods 0.000 claims description 15
- 239000003507 refrigerant Substances 0.000 claims description 14
- 229910001220 stainless steel Inorganic materials 0.000 claims description 10
- 239000010935 stainless steel Substances 0.000 claims description 10
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- 229910052802 copper Inorganic materials 0.000 claims description 9
- 239000010949 copper Substances 0.000 claims description 9
- 230000005484 gravity Effects 0.000 claims description 9
- 238000007789 sealing Methods 0.000 claims description 8
- 238000007599 discharging Methods 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 6
- 238000011176 pooling Methods 0.000 claims description 6
- 238000003860 storage Methods 0.000 claims description 5
- 238000004781 supercooling Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 abstract description 30
- 230000008569 process Effects 0.000 abstract description 23
- 239000003245 coal Substances 0.000 abstract description 8
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 238000012544 monitoring process Methods 0.000 abstract description 4
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 abstract description 2
- 239000003795 chemical substances by application Substances 0.000 abstract 2
- 238000005057 refrigeration Methods 0.000 abstract 2
- 239000002994 raw material Substances 0.000 abstract 1
- 208000003173 lipoprotein glomerulopathy Diseases 0.000 description 15
- 241000196324 Embryophyta Species 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- 238000009833 condensation Methods 0.000 description 5
- 230000005494 condensation Effects 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 150000001335 aliphatic alkanes Chemical class 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000002360 explosive Substances 0.000 description 3
- 239000002737 fuel gas Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 230000003416 augmentation Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000007726 management method Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 230000032258 transport Effects 0.000 description 2
- 241000519996 Teucrium chamaedrys Species 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 125000000816 ethylene group Chemical class [H]C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000001802 infusion Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000010183 spectrum analysis Methods 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
- F25J1/0045—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by vaporising a liquid return stream
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/0002—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the fluid to be liquefied
- F25J1/0022—Hydrocarbons, e.g. natural gas
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0032—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration"
- F25J1/004—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using the feed stream itself or separated fractions from it, i.e. "internal refrigeration" by flash gas recovery
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0201—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using only internal refrigeration means, i.e. without external refrigeration
- F25J1/0202—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using only internal refrigeration means, i.e. without external refrigeration in a quasi-closed internal refrigeration loop
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
- F25J1/0258—Construction and layout of liquefaction equipments, e.g. valves, machines vertical layout of the equipments within in the cold box
-
- 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
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/62—Separating low boiling components, e.g. He, H2, N2, 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
- F25J2220/00—Processes or apparatus involving steps for the removal of impurities
- F25J2220/60—Separating impurities from natural gas, e.g. mercury, cyclic hydrocarbons
- F25J2220/64—Separating heavy hydrocarbons, e.g. NGL, LPG, C4+ hydrocarbons or heavy condensates in general
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 utility model relates to a device for liquefying the natural gas. The utility model utilizes only a compressor to compress the circulating refrigeration agent which comprises propane, ethane and methane and the raw material natural gas, and further liquefy the natural gas. The utility model comprises a compressor, a cooler, a separating box of each component, a cooler of each component, a separating box for the non-condensing gas and the liquid natural gas storing tank, which are connected in order. Solving the practical problems that only two airflows participate in heat exchange in the processes of step evaporating and absorbing back relative components in the circulating refrigeration agent, the utility model provides a device which controls the back-absorbing volume of each component through a liquid level monitoring method. The utility model simplifies the structure of the device and the operating art. Having low production and operating cost, the utility model is applicable to the liquefying of the residual gas pumped from the coal bed and can not be utilized completely or natural gas in deserted wells having no developing value, and the daily output of the residual gas or the natural gas in deserted wells is preferably less than 50000 Nm 3.
Description
Technical field
The utility model relates to the liquefying plant of combustion gas, relates in particular to the device that natural gas that methane content is produced at the coal bed gas more than 90%, low yield gas well liquefies.
Background technology
Comprised alkanes fuel gas in the component of coal bed gas (also claiming Device in Gas) based on methane.The natural gas of exploiting out from gas well also is the alkanes fuel gas based on methane.So in this case, both unified natural gases that calls.
Wherein, the natural gas in the coal seam is the arch-criminal that the colliery gas explosion takes place, causes mine disaster.One of way that prevents gas explosion is earlier natural gas to be extracted out by the collecting pipe that pierces in the coal seam before seam mining.Near resident's the daily life natural gas of extracting out all is used for.But too much at the natural gas of extracting out, near resident when toing many or too much for use, just having to runs in these exhaustless natural gas straights to put or be allowed to condition in the atmosphere burns.Like this, not only cause great waste, but also had influence on environment.If can be liquid natural gas (LNG) with these coal gas gasifications, be transported to the city of closing on, in supply station after the vaporization, resupply civilian or to the refueling comparatively feasible scheme of will can yet be regarded as with tank car.Five, the sixties, early had natural gas liquefaction device abroad, China has also introduced several.At present, by domestic deep cooling industry and research institutions' independent research, also produced many.From the liquefaction flow path aspect, above-mentioned existing apparatus adopts the cascade system of multi-stage compression mostly, promptly adopts the independently circulation separately of cold-producing mediums such as freon, propane, ethane, nitrogen.For reclaiming callable energy as much as possible, also used decompressor to recover energy in its system as throttling arrangement.In addition, no matter above that a kind of liquefying plant, its heat-exchanger rig has all adopted the aluminum plate-fin type high-performance heat exchanger.
Yet, because the daily output of external natural gas liquefaction device is all at hundreds of thousands～millions of Nm
3Between, the daily output of the natural gas liquefaction device of domestic independent research also is not less than 50000Nm
3And single group coal bed gas well yield is generally all little, usually only at 5000～20000Nm
3Between/day.Therefore, no matter be to introduce abroad, or buy domestic independent research, not only the natural gas liquefaction in single group coal seam is seemed excessive, and operating cost is also very high.In addition, various places are in the natural gas drilling process, because of the daily output is crossed low unprofitable substantially abandoned well (just having about 200～300 mouthfuls) also quite a lot in the scope of Chongqing.Equally also need to be fit to the natural gas liquefaction device of its corresponding gas production, so that these abandoned wells obtain utilizing.But, at present at home and abroad all less than suitable its daily output less than 50000Nm
3, natural gas liquefaction device that operating cost is cheap.Reason be present these separately independent cooling agent circulation liquid device, need multiple compressors, multiply air-flow to carry out heat exchange, all be not suitable for midget plant from investment, processing technology and operational management aspect.
Say that in theory only the natural gas liquefaction that compresses full mix refrigerant with the separate unit compressor is feasible.But up to the present, also only rest in the theoretic discussion, go back the real utility unit of implementing of neither one so far.
The utility model content
First purpose of the present utility model is, provides a kind of and is suitable for little gas production (daily output is less than 50000Nm
3) small-scaled natural gas liquification device.
Second purpose of the present utility model is that a kind of apparatus structure with low cost, can monitor and adjust the mix refrigerant ratio in small-scaled natural gas liquification device is provided.
For reaching first purpose of the present utility model, provide a kind of like this device of natural gas liquefaction.In this device, compressor only has one, and what compress by this compressor is to have removed the raw natural gas of impurity and the circulating refrigerant that is formed by propane, ethene, methane blended; Wherein, the weight mixing ratio of propane, ethene and methane is that (specify: natural gas itself was exactly based on the alkanes fuel gas of methane content in 1.76: 1.27: 1.0, the utility model puts forward methane separately and natural gas difference statement, be because this part methane is brought as the cold-producing medium utilization in the process of preparation liquefied natural gas and finally do not stored and transport outward with liquefied natural gas, but return compressor) as backflow.
The equipment that connects successively after this compressor comprises:
Cooling is from first aftercooler of the HTHP mist of compressor output;
The heavy hydrocarbon component that brings from raw natural gas, be condensed into liquid through cooling separated from this mist and this heavy hydrocarbon component get rid of from its bottom, the heavy hydrocarbon separator box of this mist from its top output;
The mist of having removed the heavy hydrocarbon component is cooled off, with second aftercooler of the biphase gas and liquid flow that obtains having LPG;
The propane fluid separation applications case of the gravity type that LPG is separated from the biphase gas and liquid flow at its place---isolated LPG is from the bottom output of this propane fluid separation applications case, and remaining mist is from the top output of this propane fluid separation applications case;
One allows the remaining mist that has separated propane enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid ethylene, after allowing LPG by a choke valve throttling step-down that bottom propane fluid separation applications case, communicates simultaneously, entering the amount that need return propane flammable gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles evaporates, and the propane flammable gas that evaporation is obtained be transmitted back to go in the compressor before, cool off earlier the propane cooler of the mist in this dish type heat exchanger tube as cold-producing medium;
The Ethylene Liquid separator box of the gravity type that liquid ethylene is separated from the biphase gas and liquid flow at its place---isolate the bottom output of liquid ethylene from this Ethylene Liquid separator box, remaining mist is from the top output of this Ethylene Liquid separator box;
One allows the remaining mist that has separated ethene enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid methane, after allowing liquid ethylene by a choke valve throttling step-down that bottom the Ethylene Liquid separator box, communicates simultaneously, entering the amount that need return ethylene gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles evaporates, and ethylene gas that evaporation is obtained be transmitted back to through propane cooler go in the compressor before, cool off the ethylene chiller of the mist in this dish type heat exchanger tube earlier as cold-producing medium;
The biphase gas and liquid flow that has separated ethene and had a liquid methane imported in the dish type heat exchanger tube that is provided with in its shell space a return-air cooler of further cooling and liquefaction;
The methane fluid separation applications case of a gravity type that is connected with this return-air cooler by a choke valve, liquid methane is separated from the biphase gas and liquid flow at its place---isolate the bottom output of liquid methane from this methane fluid separation applications case, remaining natural gas is from the top output of this methane fluid separation applications case;
The remaining natural gas that handle has separated liquid methane enters further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, allow simultaneously isolated liquid methane by with a choke valve throttling step-down that methane fluid separation applications case bottom communicates after, in its lower housing portion enters its shell space according to keeping the required methane tolerance evaporation of mixing ratio, and the methane gas that evaporation obtains cooled off as cold-producing medium and this dish type heat exchanger tube that liquefies in the methane cooler of natural gas;
The upper end of an interior dish type heat exchanger tube that is provided with of its shell space and the dish type heat exchanger tube lower end UNICOM in the methane housing of cooler body space, its dish type heat exchanger tube lower end is by the liquefied natural gas subcooler of a control valve and a liquid natural gas holding vessel UNICOM---between this liquid natural gas holding vessel and liquefied natural gas subcooler housing, be serially connected with a return-air valve that opens and closes simultaneously with control valve;
And the choke valve and methane cooler casing of methane fluid separation applications case bottom UNICOM between, be connected with a branched pipe; The housing UNICOM of the other end of this branched pipe and liquefied natural gas subcooler to allow by the methane after this choke valve throttling step-down, does further supercooling to the natural gas in the dish type heat exchanger tube in this liquefied natural gas subcooler simultaneously.Between the housing bottom between the housing middle part of the case top of this liquefied natural gas subcooler and methane cooler, at the case top of this methane cooler and return-air cooler, between in the middle part of the housing of the case top of this return-air cooler and ethylene chiller, respectively be connected with a muffler.
Further improve and be, an incoagulable gas separator box has been advanced in series connection between two groups of dish type heat exchanger tubes of methane cooler and liquefied natural gas subcooler, and this incoagulable gas separator box is made of with the flash chamber that is positioned at its underpart the incoagulable gas separation chamber that is positioned at its top.The dish type heat exchanger tube UNICOM of this incoagulable gas separation chamber and methane cooler, an incoagulable gas delivery pipe is arranged at its top; The dish type heat exchanger tube UNICOM of the bottom of this flash chamber and liquefied natural gas subcooler, its top is by the housing UNICOM of a choke valve and methane cooler; Pass through a choke valve UNICOM between incoagulable gas separation chamber and the flash chamber.
Further improving is that in said apparatus, all dish type heat exchanger tubes are made by low temperature resistant stainless steel tube or copper pipe.
For reaching second purpose of the present utility model, provide a kind of like this and can in small-scaled natural gas liquification device, monitor and the apparatus structure of adjusting the mix refrigerant ratio.This apparatus structure is: in propane cooler and ethylene chiller, respectively be connected with a liquid level gauge that is filled with painted refrigerator oil in it.Be the liquid sealing pipe UNICOM of being inverted the U font by one section between the bottom of the lower end of each liquid level gauge and each corresponding cooler, the headroom UNICOM of the upper end of each liquid level gauge and corresponding cooler.Near liquid level gauge one side the painted refrigerator oil storage tube that has enlarged diameter in a section is arranged at this liquid sealing pipe.Under LPG in propane cooler and ethylene chiller bottom, the liquid ethylene liquid level discharging tube is arranged respectively, a blowdown pipe is respectively arranged on this liquid level, and the media outlet that is cooled in propane cooler and ethylene chiller bottom respectively has a point for measuring temperature.
Compare with the device of existing natural gas liquefaction, superiority of the present utility model is as follows:
1, from the scheme that realizes first purpose of the present utility model as can be seen, because the utility model is according to the needs of miniaturization, only adopted a compressor to compress multiple cold-producing medium and substituted the decompressor in the existing apparatus with choke valve, like this, only on higher compressor of expense ratio and decompressor, just saved a large amount of costs.After being well understood to device of the present utility model, those skilled in the art can enough public methods (and instrument) monitor and adjust the ratio that is transmitted back to each component in the mix refrigerant that goes in the compressor fully.For example, combine with light spectrum analysis method and control automatically, adjustment.Like this, both overcome in existing large-scale plant the sort of separately independently the circulatory system, multiply air-flow carry out heat exchange, and need the defective of multiple compressors, complicated heat exchanger equipment and complicated technology; Again the natural gas liquefaction (promptly only having heat exchange in device between two strands of air-flows) of the full mix refrigerant that only compresses with the separate unit compressor rise to can practice degree.
2, as can be seen, because the dish type heat exchanger tube (being heat exchanger) in this device is made by low temperature resistant stainless steel tube or copper pipe from the further improvement part of realizing first purpose of the present utility model.So, changeable to the component that coal bed gas, this class of low yield gas well gas have, the uncertain source of the gas of impurity content in the unstripped gas just needn't be as treating aluminum plate-fin heat exchanger of the prior art, and must fully purify unstripped gas in advance could long-term, the operation reliably of assurance equipment.Remove that impurity (has generally included H in the raw natural gas
2S, SO
2, CO
2, H
2O, N
2, O
2And Hg etc.) after requirement reduced, equipment cost and operating cost had been saved many again.
3, for ease of understanding, realize the monitoring and principle and the operating process of adjusting the mix refrigerant ratio of the utility model second destination device structure, in having " specific embodiment " of Reference numeral, introduce, only introduce its advantage in this part.Its advantage is, saved spectroanalysis instrument etc. and has been used in the instrument that its price too seems expensive in the small-scaled natural gas liquification device, saved a large sum of training, management and maintenance funds.
In addition, compared with prior art, owing in the utility model, reduced or simplified capital equipment and pertinent instruments, so package unit just can manufacture the version of being convenient to cut to, for example: skid-mounted type.Like this, package unit just had a good applicability, its utilization rate is also just bigger.
Below in conjunction with accompanying drawing the utility model is further described.
Description of drawings
Fig. 1---the system schematic of the utility model natural gas liquefaction device
Fig. 2---propane in the utility model (or ethene) fluid separation applications case and propane (or ethene) cooler package are combined into the structural representation (two assemblies are basic identical, just in the assembly that Ethylene Liquid separator box and ethylene chiller are combined into less than the ethylene gas muffler that is drawn by double dot dash line) of a component devices
Fig. 3---methane fluid separation applications case, methane cooler, incoagulable gas separator box, liquefied natural gas subcooler and liquefied natural gas subcooler are combined as the structural representation of a component devices in the utility model
The specific embodiment
A kind of device of natural gas liquefaction (with reference to figure 1).In this device, compressor 1 is only used one (obviously, in order to guarantee enough outlet pressures, selected compressor 1 should be double-stage compressor at least), what compress by this compressor 1 is to have removed the raw natural gas of impurity and the circulating refrigerant that is formed by propane, ethene, methane blended; Wherein, the weight mixing ratio of propane, ethene and methane is 1.76: 1.27: 1.0.
The equipment that connects successively after this compressor 1 comprises:
Cooling is from first aftercooler 2 of the HTHP mist of compressor 1 output;
The heavy hydrocarbon component that brings from raw natural gas, be condensed into liquid through cooling separated from this mist and this heavy hydrocarbon component get rid of from its bottom, (the heavy hydrocarbon component of eliminating is a liquid from a heavy hydrocarbon separator box 3 of its top output this mist, it can be vaporized once more, as fuel; Or with liquid situation sale);
The mist of having removed the heavy hydrocarbon component is cooled off, with second aftercooler 4 (first and second coolers are bought commercially available water-cooled cooler and get final product, and are common, provide by Compressors Factory is supporting) of the biphase gas and liquid flow that obtains having LPG;
The propane fluid separation applications case 5 (with reference to figure 2) of the gravity type that LPG is separated from the biphase gas and liquid flow at its place---isolated LPG is from the bottom output of this propane fluid separation applications case 5, and remaining mist is from the top output of this propane fluid separation applications case 5;
One allows the remaining mist that has separated propane enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid ethylene, allow simultaneously LPG by with a choke valve 6 throttling step-downs that propane fluid separation applications case 5 bottoms communicate after, entering the amount that need return propane flammable gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles (this specific embodiment is 12) evaporates, and the propane flammable gas that evaporation is obtained be transmitted back to go in the compressor 1 before, cool off earlier the propane cooler 7 (with reference to figure 2) of the mist in this dish type heat exchanger tube as cold-producing medium;
The Ethylene Liquid separator box 8 (with reference to figure 2) of the gravity type that liquid ethylene is separated from the biphase gas and liquid flow at its place---isolate the bottom output of liquid ethylene from this Ethylene Liquid separator box 8, remaining mist is from the top output of this Ethylene Liquid separator box 8;
One allows the remaining mist that has separated ethene enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid methane, after allowing liquid ethylene by a choke valve 9 throttling step-downs that communicate with Ethylene Liquid separator box 8 bottoms simultaneously, entering the amount that need return ethylene gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles (this specific embodiment is 12) evaporates, and ethylene gas that evaporation is obtained be transmitted back to through propane cooler 7 go in the compressor 1 before, cool off the ethylene chiller 10 (with reference to figure 2) of the mist in this dish type heat exchanger tube earlier as cold-producing medium;
The biphase gas and liquid flow that has separated ethene and had a liquid methane imported in the dish type heat exchanger tube that is provided with in its shell space a return-air cooler 11 of further cooling and liquefaction;
A gravity type 11 that be connected by a choke valve 12 and this return-air cooler, that liquid methane is separated from the biphase gas and liquid flow at its place methane fluid separation applications case 13 (with reference to figure 3)---isolate the bottom output of liquid methane from this methane fluid separation applications case 13, remaining natural gas is from the top output of this methane fluid separation applications case 13;
The remaining natural gas that handle has separated liquid methane enters further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, allow simultaneously isolated liquid methane by with a choke valve 14 throttling step-downs that methane fluid separation applications case 13 bottoms communicate after, in entering its shell space, its lower housing portion evaporates according to the required methane tolerance of maintenance mixing ratio, and the methane gas that evaporation obtains cooled off as cold-producing medium and this dish type heat exchanger tube that liquefies in the methane cooler 15 of natural gas (with reference to figure 1, Fig. 3)---that is to say, in this methane cooler 15, natural gas should liquefy.Therefore, in order to ensure there being enough methane refrigerant to enter in this methane cooler 15, can by adjusting be arranged in the following branched pipe control valve 141 apertures or by the different restricting orifice of its pore size be set respectively on the branched pipe pipeline realize upper and lower the stating of the pipeline that enters this methane cooler 15 behind the choke valve 14;
The upper end of an interior dish type heat exchanger tube that is provided with of its shell space and the dish type heat exchanger tube lower end UNICOM in methane cooler 15 shell spaces, its dish type heat exchanger tube lower end is by the liquefied natural gas subcooler 19 (with reference to figure 3) of a control valve 201 and liquid natural gas holding vessel 20 UNICOMs---between this liquid natural gas holding vessel 20 and liquefied natural gas subcooler 19 housings, be connected to the return-air valve 191 of a steady pressure, so that be heated when boosting or annotating liquid natural gas, to the gaseous natural gas of liquefied natural gas subcooler 19 discharging superpressures at liquid natural gas holding vessel 20;
And the choke valve 14 and methane cooler 15 housings of methane fluid separation applications case 13 bottom UNICOMs between, be connected with a branched pipe.The housing UNICOM of the other end of this branched pipe and liquefied natural gas subcooler 19, to allow, simultaneously the natural gas in the dish type heat exchanger tube in this liquefied natural gas subcooler 19 is done further supercooling (purpose is to reduce the evaporation loss of liquefied natural gas in storage and transportation) by the methane after the 14 throttling step-downs of this choke valve.Between the housing bottom between the housing middle part of the case top of this liquefied natural gas subcooler 19 and methane cooler 15, at the case top of this methane cooler 15 and return-air cooler 11, between in the middle part of the housing of the case top of this return-air cooler 11 and ethylene chiller 10, respectively be connected with a muffler.
Further, for device of the present utility model can move very reliably, in this specific embodiment, in the casing of propane fluid separation applications case 5, Ethylene Liquid separator box 8 and methane fluid separation applications case 13, the remaining mist of a chimney-like or the discharge pipe of remaining natural gas are arranged all; The outer space of this discharge pipe is the separation chamber, and each choke valve (6,9,14) that is connected this propane fluid separation applications case 5, Ethylene Liquid separator box 8 and methane fluid separation applications case 13 bottoms is connected this bottom, separation chamber; Bottom in this discharge pipe have one with they the remaining mist that communicates of the dish type heat exchanger tube upper end of UNICOM or the pooling zone B of remaining natural gas separately; In the bottom of propane cooler 7, ethylene chiller 10 and liquefied natural gas subcooler 19, have respectively that its top communicates with the lower end of dish type heat exchanger tube, its bottommost has a pooling zone A (with reference to figure 2, Fig. 3) who is connected to drain pipe.
Further say, for the incoagulable gas that is not subjected to bring from raw natural gas influences, with guarantee to compress, the process of liquefied natural gas can go on constantly.In this specific embodiment, an incoagulable gas separator box 17 has been advanced in series connection between two groups of dish type heat exchanger tubes of methane cooler 15 and liquefied natural gas subcooler 19, and this incoagulable gas separator box 17 is made of with the flash chamber that is positioned at its underpart the incoagulable gas separation chamber that is positioned at its top.The dish type heat exchanger tube UNICOM of this incoagulable gas separation chamber and methane cooler 15, an incoagulable gas delivery pipe 21 is arranged at its top; The dish type heat exchanger tube UNICOM of the bottom of this flash chamber and liquefied natural gas subcooler 19, its top is by the housing UNICOM of a choke valve 16 with methane cooler 15; Pass through choke valve 18 UNICOMs between incoagulable gas separation chamber and the flash chamber.
In this specific embodiment, propane fluid separation applications case 5 and propane cooler 7, Ethylene Liquid separator box 8 and ethylene chiller 10, all with separately separator box last, separately cooler under form be combined as respectively component devices; Dish type heat exchanger tube is wherein made (with reference to figure 2) by low temperature resistant stainless steel tube or copper pipe.
In this specific embodiment, in accordance with the order from top to bottom, methane fluid separation applications case 13, methane cooler 15, incoagulable gas separator box 17 and liquefied natural gas subcooler 19 are combined as a component devices; Dish type heat exchanger tube is wherein made (with reference to figure 3) by low temperature resistant stainless steel tube or copper pipe.
Certainly, other parts in the utility model device also can all be made with low temperature resistant stainless steel.
As previously mentioned, be transmitted back to the ratio of each component in the mix refrigerant that goes in the compressor 1, should monitor and adjust and can monitor and adjust with public method fully.In this specific embodiment, a kind of monitoring and adjustment structure (with reference to figure 2) of this class small-scaled natural gas liquification device of suitable the utility model have then been adopted.Its architectural feature is, in propane cooler 7 and ethylene chiller 10, respectively is connected with a liquid level gauge 23 that is filled with painted refrigerator oil in it.Be the liquid sealing pipe UNICOM of being inverted the U font by one section between the bottom of the lower end of each liquid level gauge 23 and each corresponding cooler, the headroom UNICOM of the upper end of each liquid level gauge 23 and corresponding cooler; Near liquid level gauge 23 1 sides the painted refrigerator oil storage tube that has enlarged diameter in a section is arranged at this liquid sealing pipe, the highest point of this liquid sealing pipe generally should be higher than the LPG in each corresponding cooler bottom, the liquid level of liquid ethylene.Under LPG in propane cooler 7 and ethylene chiller 10 bottoms, the liquid ethylene liquid level discharging tube 24 is arranged respectively, a blowdown pipe 22 is respectively arranged on this liquid level, and the media outlet that is cooled in propane cooler 7 and ethylene chiller 10 bottoms respectively has a point for measuring temperature 25.
To the gas deliquescence process in the above-mentioned specific embodiment (step), do more detailed introduction below.
A, the raw natural gas that will remove impurity and circulating refrigerant suck in this compressor 1 together, the step to compress.In this step, the outlet pressure of compressor 1 is 3.0Mpa～4.0Mpa, and outlet temperature is 120 ℃～140 ℃.
B, step to from the HTHP mist input cooler 2 of this compressor 1 output, cooling off.In this step, the temperature after mist is cooled is 79 ℃～81 ℃.
C, heavy hydrocarbon component that will bring from raw natural gas in heavy hydrocarbon separator box 3, be condensed into liquid through cooling separate and get rid of the step of this heavy hydrocarbon component from this mist.
D, the mist of having removed the heavy hydrocarbon component is cooled off at aftercooler 4, with the step of the biphase gas and liquid flow that obtains having LPG.In this step, the temperature after mist is cooled is 30 ℃～35 ℃.
E, in propane fluid separation applications case 5, LPG is separated from the biphase gas and liquid flow at its place; Carry out the throttling step-down by 6 pairs of these LPGs of choke valve then, allow its required amount evaporation of returning propane flammable gas in the casing of propane fluid separation applications case 5 according to keeping mixing ratio, and borrow its evaporation endothermic process to come the remaining mist in the dish type heat exchanger tube in propane fluid separation applications case 5 is further cooled off, to obtain having the biphase gas and liquid flow of liquid ethylene, then propane flammable gas is transmitted back to the step of going in the compressor 1.In this step, the pressure after its LPG throttling step-down is 0.102Mpa～0.105Mpa, at this moment, the temperature of having evaporated and not evaporated the biphase gas and liquid flow of propane after the throttling is-42 ℃～-40 ℃.The resulting temperature that has the biphase gas and liquid flow of liquid ethylene in back that is cooled is-38 ℃～-36 ℃.
In f, the Ethylene Liquid separator box 8 liquid ethylene is separated from the biphase gas and liquid flow at its place, carry out the throttling step-down, allow the ethene tolerance evaporation that it need return according to keeping mixing ratio in the casing of Ethylene Liquid separator box 10 by 9 pairs of these liquid ethylenes of choke valve then, and borrow its evaporation endothermic process to come the mist of the remainder in the dish type heat exchanger tube in Ethylene Liquid separator box 10 is further cooled off, obtaining having the biphase gas and liquid flow of liquid methane, then ethylene gas is transmitted back to the step of going in the compressor 1 after by propane fluid separation applications case 5.In this step, pressure after its liquid ethylene throttling step-down is 0.102Mpa～0.105Mpa, the temperature of having evaporated and not evaporated the biphase gas and liquid flow of ethene after the throttling is-103 ℃～-102 ℃, and the resulting temperature that has the biphase gas and liquid flow of liquid methane in cooling back is-98 ℃～-97 ℃.
G, in return-air cooler 11, the biphase gas and liquid flow that has liquid methane is further cooled off; By choke valve 12 its throttling is depressured to 1.25Mpa～1.6Mpa then, after temperature drops to-119 ℃, in methane fluid separation applications case 13, liquid methane is separated from the biphase gas and liquid flow at its place with as cooling medium again; Then be divided into two-way output by choke valve 14 relief methane liquid.
H, this methane liquid major part enter the interior evaporation of casing of methane cooler 15, with the liquid that is cooled in the dish type heat exchanger tubes in the methane cooler 15, allow this liquified natural gas enter in the incoagulable gas separator box 17 then, to separate and discharging incoagulable gas wherein by choke valve 18; Then the liquified natural gas that has separated incoagulable gas is input in the dish type heat exchanger tube in the liquefied natural gas subcooler 19, imports methane refrigerant in these liquefied natural gas subcooler 19 casings into from another road to its supercooling (cold excessively) to allow.In this step, afterwards as cooling medium, the pressure after its step-down is 0.102Mpa～0.105Mpa to liquid methane by the throttling step-down, and temperature is-163 ℃～-162 ℃.
I, last sends into liquid natural gas holding vessel 20 to overcooled liquified natural gas by control valve 201, transports outward waiting.In opening controlling valve 201, open the return-air valve 191 of UNICOM's natural gas storage tanks 20 and liquefied natural gas subcooler 19.
Wherein, be to come as the methane gas of cold-producing medium in return-air cooler 11 casings by many muffler loopbacks that are together in series with several casings thereafter respectively.Also be connected with a muffler between these return-air cooler 11 casings and Ethylene Liquid separator box 10 casings.
Below, be example with propane fluid separation applications case 5 with propane cooler 7 again, be combined in the entire work process in this component devices, introduce the principle and the process of monitoring and adjusting described circulating refrigerant mixing ratio: isolated propane liquid in propane fluid separation applications case 5, after choke valve 6 throttling step-downs, the shell space that enters propane cooler 7 (preferably, spray into by several nozzles of arranging around propane cooler 7, with augmentation of heat transfer), be subjected to natural gas mobile in the dish type heat exchanger tube from top to bottom, the heating of methane and ethylene gas and part evaporation, unevaporated propane liquid then drops to the bottom of shell space, form liquid level, continuation is by the natural gas in the dish type heat exchanger tube, methane and the heating of ethene medium, and continuously explosive evaporation.The propane gas that is evaporated, converge methane and ethylene gas, be heated the back together and flow out from top and return compressor 1 from ethylene chiller 10.The natural gas that is cooled in the coil pipe, methane and ethylene gas, in the decline process, ethene wherein begins to condense into liquid, finally become Ethylene Liquid and steam methane mixture, discharge from propane cooler 7 bottoms, enter Ethylene Liquid separator box 8.
Analyze the inside and outside diabatic process of coil pipe in the propane cooler 7, its top is natural gas, ethene and the methane gas diabatic process for propane gas and backflow gas, is called the diabatic process of gas phase and gas phase.At the middle part, rise when ethene begins condensation in the coil pipe, the coil pipe outside mainly remains propane flammable gas and backflow gas (effect of augmentation of heat transfer is only played in the effect of spray), and therefore, the middle part is the diabatic process of condensation and gas phase; In the bottom, when coil pipe enters the propane liquid level when following, just become the diabatic process of condensation and explosive evaporation.Show the size of the heat transfer coefficient of middle part condensation and gas phase, genus hundred figure place grades by calculating to the different heat transfer process; And the heat transfer coefficient of bottom condensation and explosive evaporation, its size are the thousands digit grades, and both differ an order of magnitude.Therefore, if change the liquid level of propane in propane cooler 7 housings, just can change the additional issue amount of propane significantly.In other words, control the evaporation capacity that liquid level also just can be controlled propane, also promptly returned the propane reflux amount of compressor 1.
The method of propane liquid level is very simple and easy in the control housing, and the aperture that only needs to change choke valve 6 just can reach.Open when big when choke valve 6, liquid level will rise; Otherwise, choke valve 6 descends when closing hour liquid level.This operating process, required choke valve 6 and liquid level gauge 23 all are placed on the panel of incubator (also the claiming ice chest) casing in the actual device.It must be noted that, the propane liquid in liquid level gauge 23 tube connectors after long-term the stop, all can flash to gas, can not reflect actual liquid level.Therefore, must fill other in the liquid level gauge 23 can evaporated liquid, and this specific embodiment is painted refrigerator oil, and the liquid level of propane is to change by the propane flammable gas pressure in the liquid sealing pipe of being inverted the U font to transmit.
When regulating the aperture of choke valve 6, must be noted that following 2 points:
(1) aperture of choke valve 6 can not be excessive, otherwise the propane liquid level in the propane fluid separation applications case 5 will be lower than the mouth of pipe of propane fairlead, make methane, natural gas and ethylene gas enter propane cooler 7 housings in a large number, and be back to compressor 1 inlet, cause the invalid circulation of above-mentioned gas, reduce natural gas liquefaction output greatly.For this reason, propane fluid separation applications case 5 has also been installed liquid level gauge, to prevent propane liquid level low excessively (Ethylene Liquid separator box 8 is as the same).
(2) though open the cooling effect that big choke valve 6 can improve natural gas in the coil pipe, ethene and methane, help the liquefaction of natural gas.But choke valve 6 apertures are excessive, must increase the evaporation capacity of propane, tie up the share of other cold-producing mediums, cause out of proportion.Therefore, the aperture of choke valve 6 should keep suitable position, so that the outlet temperature of the Ethylene Liquid of propane cooler 7 and natural gas (biphase gas and liquid flow that promptly has liquid ethylene) remains in-38 ℃～-36 ℃, must not be lower than-38 ℃ [among Fig. 2, measuring the bottom of the point for measuring temperature 25 of outlet temperature] at these propane cooler 7 housings (low head).
Propane liquid level in the said temperature scope, in the cooler casing is the control liquid level.But this liquid level can constantly raise in running, and this is because the reason that contains the propane component in the raw natural gas, constantly liquefies in the liquefaction cycle process, also here constantly gathers.For this reason, the throttle valve opening that should regulate on the discharging tube 24 carries out continuous blow-down, to keep the substantially constant of propane liquid level.In general, the frequency of revising operation is very little.In case of necessity, discharge process can be implemented by Liquid level adjusting valve.
Profit uses the same method, and can regulate the ethylene gas of backflow.Be noted that, because the content of ethene is extremely low in the raw natural gas, in gas deliquescence process, have small amount of ethylene and be dissolved in the liquefied natural gas and constantly be pulled away, so in the ordinary course of things, here to be operating as the master from blowdown pipe 22 inside tonifying Qi.
For the control of methane liquid level in methane cooler 15 housings, its method is identical with two coolers.Its difference is for no other reason than that the main component in the raw natural gas is a methane, the operation of fluid infusion and discharge opeing recedes into the background, only need to regulate the throttle valve opening on the methane fluid separation applications case 13 back methane liquid fairleads, the temperature of control methane cooler 15 bottom methane liquid, that it is remained between-120 ℃～-119 ℃ is just passable.
Because three coolers in the whole liquefaction flow path (is that housing liquid level between propane cooler 7, ethylene chiller 10 and the methane cooler 15 is to be mutually related, the liquid level of regulating any one cooler all can cause the variation of the middle liquid level of other coolers, therefore, the adjustment of each throttle valve opening need be carried out just finishing for 2～3 times repeatedly.
Below, the separation and the emissions operation of incoagulable gas is further described.
So-called incoagulable gas is meant the N that contains in the raw natural gas
2, O
2And the gases such as He, Ar of trace, their condensing temperature is all much lower than the condensing temperature of natural gas itself.Therefore, in gas deliquescence process, they are present in the circulatory system with the form of gas, if not with its discharge system, then this class gas constantly accumulates in system, ties up the capacity share of compressor 1, makes the decline of exerting oneself of liquefying plant.What is more, the existence of incoagulable gas, and the diabatic process of each heat exchanger in the liquefying plant that deteriorates significantly, thereby further reduced exerting oneself of liquefying plant.This situation occurred in many homemade liquefying plants.Several liquefying plants do not reach exerts oneself, and this may be a main cause.
In this liquefying plant, methane cooler 15 bottoms, natural gas (wherein main component is a methane) that are positioned at 1.25Mpa～1.3Mpa major part obtain liquefaction, the temperature of liquid is between-120 ℃～-119 ℃, and the steam methane partial pressure on the liquid level should also be between 1.25Mpa～1.3Mpa.But the incoagulable gas accumulation is here constantly arranged, and the partial pressure of supposing these gases is P, and this partial pressure P value raises, makes gross pressure to surpass 1.25Mpa～1.3Mpa along with the continuous accumulation of these gases, and in continuous rising.If these incoagulable gas in the supposition raw natural gas (mainly are N
2) content about 5%, in order to get rid of this part gas, must drain useful natural gas together simultaneously.According to calculating, if the discharge capacity of control natural gas useful component total liquefied natural gas amount 1% in, should control the interior pressure of exhaust chamber between 1.5Mpa～1.6Mpa, this can regulate the preceding choke valve 12 of methane fluid separation applications case and the choke valve 211 on the incoagulable gas delivery pipe reaches.The capacity of this moment is about about 6% of the total air inflow of unstripped gas, and wherein 1% is active ingredient.
Realize that the item that above measure should be noted is: no matter exhaust chamber bottom liquid pressure surpasses 1.25Mpa～1.3Mpa and reaches 1.5Mpa～1.6Mpa, but the temperature of exhaust chamber bottom liquid must remain between-120 ℃～-119 ℃, can not raise because of the rising of pressure.In order to reach this purpose, can to regulate methane fluid separation applications case 13 bottom choke valves 14 and reach.
Pressure in the utility model device in each casing (tank body) is measured (with reference to figure 3 by the pressure gauge that is arranged on each corresponding pressure tap 26 place, all the other pressure taps do not omit and draw), the thermometer measure (with reference to figure 2,3, all the other points for measuring temperature do not omit and draw) that temperature in each casing (tank body) is located by being arranged on each corresponding point for measuring temperature (25,27).
Claims (10)
1. the device of a natural gas liquefaction, in this device compressor is arranged, it is characterized in that described compressor (1) only has one, what compress by this compressor (1) is to have removed the raw natural gas of impurity and the circulating refrigerant that is formed by propane, ethene, methane blended; Wherein, the weight mixing ratio of propane, ethene and methane is 1.76: 1.27: 1.0;
The equipment that connects successively afterwards at this compressor (1) comprises:
Cooling is from first aftercooler (2) of the HTHP mist of compressor (1) output;
The heavy hydrocarbon component that brings from raw natural gas, be condensed into liquid through cooling separated from this mist and this heavy hydrocarbon component get rid of from its bottom, the heavy hydrocarbon separator box (3) of this mist from its top output;
The mist of having removed the heavy hydrocarbon component is cooled off, with second aftercooler (4) of the biphase gas and liquid flow that obtains having LPG;
The propane fluid separation applications case (5) of the gravity type that LPG is separated from the biphase gas and liquid flow at its place; Isolated LPG is from the bottom output of this propane fluid separation applications case (5), and remaining mist is from the top output of this propane fluid separation applications case (5);
One allows the remaining mist that has separated propane enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid ethylene, after allowing LPG by a choke valve (6) the throttling step-down that bottom propane fluid separation applications case (5), communicates simultaneously, entering the amount that need return propane flammable gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles evaporates, and the propane flammable gas that evaporation is obtained be transmitted back to go in the compressor (1) before, cool off earlier the propane cooler (7) of the mist in this dish type heat exchanger tube as cold-producing medium;
The Ethylene Liquid separator box (8) of the gravity type that liquid ethylene is separated from the biphase gas and liquid flow at its place; Isolate the bottom output of liquid ethylene from this Ethylene Liquid separator box (8), remaining mist is from the top output of this Ethylene Liquid separator box (8);
One allows the remaining mist that has separated ethene enter further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, to obtain having the biphase gas and liquid flow of liquid methane, after allowing liquid ethylene by a choke valve (9) the throttling step-down that bottom Ethylene Liquid separator box (8), communicates simultaneously, entering the amount that need return ethylene gas in its shell space according to keeping mixing ratio at its housing middle part by several nozzles evaporates, and ethylene gas that evaporation is obtained be transmitted back to through propane cooler (7) go in the compressor (1) before, cool off the ethylene chiller (10) of the mist in this dish type heat exchanger tube earlier as cold-producing medium;
The biphase gas and liquid flow that has separated ethene and had a liquid methane imported in the dish type heat exchanger tube that is provided with in its shell space a return-air cooler (11) of further cooling and liquefaction;
The methane fluid separation applications case (13) of a gravity type that is connected with this return-air cooler (11) by a choke valve (12), liquid methane is separated from the biphase gas and liquid flow at its place; Isolate the bottom output of liquid methane from this methane fluid separation applications case (13), remaining natural gas is from the top output of this methane fluid separation applications case (13);
The remaining natural gas that handle has separated liquid methane enters further cooling in the dish type heat exchanger tube that is provided with in its shell space on its housing top, allow simultaneously isolated liquid methane by with a choke valve (14) throttling step-down that methane fluid separation applications case (13) bottom communicates after, in its lower housing portion enters its shell space according to keeping the required methane tolerance evaporation of mixing ratio, and the methane gas that evaporation obtains cooled off as cold-producing medium and this dish type heat exchanger tube that liquefies in the methane cooler (15) of natural gas;
The upper end of an interior dish type heat exchanger tube that is provided with of its shell space and the dish type heat exchanger tube lower end UNICOM in methane cooler (15) shell space, its dish type heat exchanger tube lower end is by the liquefied natural gas subcooler (19) of a control valve (201) with a liquid natural gas holding vessel (20) UNICOM; Between this liquid natural gas holding vessel (20) and liquefied natural gas subcooler (19) housing, be connected to the return-air valve (191) of a steady pressure;
And the choke valve (14) and methane cooler (15) housing of methane fluid separation applications case (13) bottom UNICOM between, be connected with a branched pipe; The housing UNICOM of the other end of this branched pipe and liquefied natural gas subcooler (19) to allow by the methane after this choke valve (14) throttling step-down, does further supercooling to the natural gas in the interior dish type heat exchanger tube of this liquefied natural gas subcooler (19) simultaneously; Between the housing bottom between the housing middle part of the case top of this liquefied natural gas subcooler (19) and methane cooler (15), at the case top of this methane cooler (15) and return-air cooler (11), between in the middle part of the housing of the case top of this return-air cooler (11) and ethylene chiller (10), respectively be connected with a muffler.
2. according to the device of the described natural gas liquefaction of claim 1, it is characterized in that an incoagulable gas separator box (17) has been advanced in series connection between two groups of dish type heat exchanger tubes of described methane cooler (15) and liquefied natural gas subcooler (19); This incoagulable gas separator box (17) is made of with the flash chamber that is positioned at its underpart the incoagulable gas separation chamber that is positioned at its top; The dish type heat exchanger tube UNICOM of this incoagulable gas separation chamber and methane cooler (15), an incoagulable gas delivery pipe (21) is arranged at its top; The dish type heat exchanger tube UNICOM of the bottom of this flash chamber and liquefied natural gas subcooler (19), its top is by the housing UNICOM of a choke valve (16) with methane cooler (15); Pass through a choke valve (18) UNICOM between incoagulable gas separation chamber and the flash chamber.
3. according to the device of claim 1 or 2 described natural gas liquefactions, it is characterized in that,, respectively be connected with a liquid level gauge (23) that is filled with painted refrigerator oil in it in described propane cooler (7) and ethylene chiller (10); Be the liquid sealing pipe UNICOM of being inverted the U font, the upper end of each liquid level gauge (23) and the headroom UNICOM of corresponding cooler by one section between the bottom liquid of the lower end of each liquid level gauge (23) and each corresponding cooler; Near liquid level gauge (23) one sides the painted refrigerator oil storage tube that has enlarged diameter in a section is arranged at this liquid sealing pipe; Under LPG in propane cooler (7) and ethylene chiller (10) bottom, the liquid ethylene liquid level discharging tube 24 is arranged respectively, a blowdown pipe 22 is respectively arranged on this liquid level, and the media outlet that is cooled in propane cooler (7) and ethylene chiller (10) bottom respectively has a point for measuring temperature (25)
4. according to the device of claim 1 or 2 described natural gas liquefactions, it is characterized in that, in the casing of described propane fluid separation applications case (5), Ethylene Liquid separator box (8) and methane fluid separation applications case (13), the remaining mist of a chimney-like or the discharge pipe of remaining natural gas are arranged all; The outer space of this discharge pipe is the separation chamber, and the described choke valve (6,9,14) that is connected this propane fluid separation applications case (5), Ethylene Liquid separator box (8) and methane fluid separation applications case (13) bottom is connected this bottom, separation chamber; Bottom in this discharge pipe have one with they the remaining mist that communicates of the dish type heat exchanger tube upper end of UNICOM or the pooling zone (B) of remaining natural gas separately; In the bottom of described propane cooler (7), ethylene chiller (10) and liquefied natural gas subcooler (19), have respectively that its top communicates with the lower end of dish type heat exchanger tube in it, its bottommost has a pooling zone (A) that is connected to drain pipe.
5. according to the device of claim 1 or 2 described natural gas liquefactions, it is characterized in that, described propane fluid separation applications case (5) and propane cooler (7), Ethylene Liquid separator box (8) and ethylene chiller (10), all with separately separator box last, separately cooler under form be combined as respectively component devices; Dish type heat exchanger tube is wherein made by low temperature resistant stainless steel tube or copper pipe.
6. according to the device of the described natural gas liquefaction of claim 2, it is characterized in that, in accordance with the order from top to bottom, described methane fluid separation applications case (13), methane cooler (15), incoagulable gas separator box (17) and liquefied natural gas subcooler (19) are combined as a component devices; Dish type heat exchanger tube is wherein made by low temperature resistant stainless steel tube or copper pipe.
7. according to the device of the described natural gas liquefaction of claim 3, it is characterized in that, in the casing of described propane fluid separation applications case (5), Ethylene Liquid separator box (8) and methane fluid separation applications case (13), the remaining mist of a chimney-like or the discharge pipe of remaining natural gas are arranged all; The outer space of this discharge pipe is the separation chamber, and the described choke valve (6,9,14) that is connected this propane fluid separation applications case (5), Ethylene Liquid separator box (8) and methane fluid separation applications case (13) bottom is connected this bottom, separation chamber; Bottom in this discharge pipe have one with they the remaining mist that communicates of the dish type heat exchanger tube upper end of UNICOM or the pooling zone (B) of remaining natural gas separately; In the bottom of described propane cooler (7), ethylene chiller (10) and liquefied natural gas subcooler (19), have respectively that its top communicates with the lower end of dish type heat exchanger tube in it, its bottommost has a pooling zone (A) that is connected to drain pipe.
8. according to the device of the described natural gas liquefaction of claim 3, it is characterized in that, described propane fluid separation applications case (5) and propane cooler (7), Ethylene Liquid separator box (8) and ethylene chiller (10), all with separately separator box last, separately cooler under form be combined as respectively component devices; Advanced under the situation of described incoagulable gas separator box (17) in series connection, in accordance with the order from top to bottom, methane fluid separation applications case (13), methane cooler (15), incoagulable gas separator box (17) and liquefied natural gas subcooler (19) are combined as a component devices; Dish type heat exchanger tube is wherein made by low temperature resistant stainless steel tube or copper pipe.
9. according to the device of the described natural gas liquefaction of claim 4, it is characterized in that, described propane fluid separation applications case (5) and propane cooler (7), Ethylene Liquid separator box (8) and ethylene chiller (10), all with separately separator box last, separately cooler under form be combined as respectively component devices; Advanced under the situation of described incoagulable gas separator box (17) in series connection, in accordance with the order from top to bottom, methane fluid separation applications case (13), methane cooler (15), incoagulable gas separator box (17) and liquefied natural gas subcooler (19) are combined as a component devices; Dish type heat exchanger tube is wherein made by low temperature resistant stainless steel tube or copper pipe.
10. according to the device of the described natural gas liquefaction of claim 7, it is characterized in that, described propane fluid separation applications case (5) and propane cooler (7), Ethylene Liquid separator box (8) and ethylene chiller (10), all with separately separator box last, separately cooler under form be combined as respectively component devices; Advanced under the situation of described incoagulable gas separator box (17) in series connection, in accordance with the order from top to bottom, methane fluid separation applications case (13), methane cooler (15), incoagulable gas separator box (17) and liquefied natural gas subcooler (19) are combined as a component devices; Dish type heat exchanger tube is wherein made by low temperature resistant stainless steel tube or copper pipe.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200720124160 CN201028930Y (en) | 2007-04-28 | 2007-04-28 | Natural gas liquefaction device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200720124160 CN201028930Y (en) | 2007-04-28 | 2007-04-28 | Natural gas liquefaction device |
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| CN201028930Y true CN201028930Y (en) | 2008-02-27 |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010128467A2 (en) * | 2009-05-08 | 2010-11-11 | Corac Group Plc | Production and distribution of natural gas |
| CN101504244B (en) * | 2009-03-13 | 2011-02-16 | 北京永记鑫经贸有限公司 | Ice box used for natural gas liquefaction system |
| CN104729233A (en) * | 2015-04-09 | 2015-06-24 | 上海理工大学 | Natural gas liquefaction system with combination of auto-cascade refrigeration system and pulse tube refrigerator |
| CN105121986A (en) * | 2013-04-11 | 2015-12-02 | 国际壳牌研究有限公司 | Method of liquefying a contaminated hydrocarbon-containing gas stream |
| CN108613013A (en) * | 2018-05-19 | 2018-10-02 | 大连理工大学 | A kind of hydrogen-feeding system and its working method of vehicle-mounted hydrogen storage cylinder |
| CN110170178A (en) * | 2019-05-27 | 2019-08-27 | 中冶焦耐(大连)工程技术有限公司 | A kind of condensing unit distilling tower top |
| US10871323B2 (en) | 2015-12-03 | 2020-12-22 | Shell Oil Company | Method of liquefying a CO2 contaminated hydrocarbon-containing gas stream |
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2007
- 2007-04-28 CN CN 200720124160 patent/CN201028930Y/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101504244B (en) * | 2009-03-13 | 2011-02-16 | 北京永记鑫经贸有限公司 | Ice box used for natural gas liquefaction system |
| WO2010128467A2 (en) * | 2009-05-08 | 2010-11-11 | Corac Group Plc | Production and distribution of natural gas |
| WO2010128467A3 (en) * | 2009-05-08 | 2011-12-29 | Corac Group Plc | Production and distribution of natural gas |
| CN105121986A (en) * | 2013-04-11 | 2015-12-02 | 国际壳牌研究有限公司 | Method of liquefying a contaminated hydrocarbon-containing gas stream |
| CN105121986B (en) * | 2013-04-11 | 2017-11-28 | 国际壳牌研究有限公司 | Make the contaminated liquefied method containing hydrocarbon stream |
| US10151528B2 (en) | 2013-04-11 | 2018-12-11 | Shell Oil Company | Method of liquefying a contaminated hydrocarbon-containing gas stream |
| CN104729233A (en) * | 2015-04-09 | 2015-06-24 | 上海理工大学 | Natural gas liquefaction system with combination of auto-cascade refrigeration system and pulse tube refrigerator |
| US10871323B2 (en) | 2015-12-03 | 2020-12-22 | Shell Oil Company | Method of liquefying a CO2 contaminated hydrocarbon-containing gas stream |
| CN108613013A (en) * | 2018-05-19 | 2018-10-02 | 大连理工大学 | A kind of hydrogen-feeding system and its working method of vehicle-mounted hydrogen storage cylinder |
| CN110170178A (en) * | 2019-05-27 | 2019-08-27 | 中冶焦耐(大连)工程技术有限公司 | A kind of condensing unit distilling tower top |
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