CN105737516A - System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion - Google Patents
System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion Download PDFInfo
- Publication number
- CN105737516A CN105737516A CN201610244448.7A CN201610244448A CN105737516A CN 105737516 A CN105737516 A CN 105737516A CN 201610244448 A CN201610244448 A CN 201610244448A CN 105737516 A CN105737516 A CN 105737516A
- Authority
- CN
- China
- Prior art keywords
- heat exchanger
- nitrogen
- natural gas
- stage heat
- mix refrigerant
- 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.)
- Pending
Links
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims abstract description 196
- 229910052757 nitrogen Inorganic materials 0.000 title claims abstract description 97
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 94
- 239000003507 refrigerant Substances 0.000 title claims abstract description 71
- 239000003345 natural gas Substances 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 35
- 239000000203 mixture Substances 0.000 claims description 47
- 238000001816 cooling Methods 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 23
- 239000007789 gas Substances 0.000 claims description 18
- 229930195733 hydrocarbon Natural products 0.000 claims description 14
- 150000002430 hydrocarbons Chemical class 0.000 claims description 14
- 239000004215 Carbon black (E152) Substances 0.000 claims description 13
- 239000002826 coolant Substances 0.000 claims description 9
- 230000036772 blood pressure Effects 0.000 claims description 8
- 238000000926 separation method Methods 0.000 claims description 6
- 239000007791 liquid phase Substances 0.000 claims description 5
- 238000012545 processing Methods 0.000 claims description 5
- 238000009834 vaporization Methods 0.000 claims description 4
- 230000008016 vaporization Effects 0.000 claims description 4
- 238000009833 condensation Methods 0.000 claims description 3
- 230000005494 condensation Effects 0.000 claims description 3
- 230000006837 decompression Effects 0.000 claims description 3
- 239000012071 phase Substances 0.000 claims description 3
- 238000010992 reflux Methods 0.000 claims description 2
- 238000005057 refrigeration Methods 0.000 abstract description 11
- 238000005265 energy consumption Methods 0.000 abstract description 8
- 239000003949 liquefied natural gas Substances 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 3
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 206010016256 fatigue Diseases 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000001465 metallisation Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 208000018299 prostration Diseases 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- 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
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
- F25J1/0235—Heat exchange integration
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
- F25J1/005—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by expansion of a gaseous refrigerant stream with extraction of work
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/003—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production
- F25J1/0047—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle
- F25J1/0052—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the kind of cold generation within the liquefaction unit for compensating heat leaks and liquid production using an "external" refrigerant stream in a closed vapor compression cycle by vaporising a liquid refrigerant 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
- F25J1/006—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures characterised by the refrigerant fluid used
- F25J1/007—Primary atmospheric gases, mixtures thereof
- F25J1/0072—Nitrogen
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0211—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle
- F25J1/0214—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as a dual level refrigeration cascade with at least one MCR cycle
- F25J1/0215—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as a dual level refrigeration cascade with at least one MCR cycle with one SCR cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0228—Coupling of the liquefaction unit to other units or processes, so-called integrated processes
- F25J1/0235—Heat exchange integration
- F25J1/0237—Heat exchange integration integrating refrigeration provided for liquefaction and purification/treatment of the gas to be liquefied, e.g. heavy hydrocarbon removal from natural gas
- F25J1/0238—Purification or treatment step is integrated within one refrigeration cycle only, i.e. the same or single refrigeration cycle provides feed gas cooling (if present) and overhead gas cooling
-
- 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
- F25J1/0262—Details of the cold heat exchange system
- F25J1/0264—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams
- F25J1/0265—Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams comprising cores associated exclusively with the cooling of a refrigerant stream, e.g. for auto-refrigeration or economizer
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
- F25J1/02—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen ; Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process
- F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
- F25J1/0279—Compression of refrigerant or internal recycle fluid, e.g. kind of compressor, accumulator, suction drum etc.
- F25J1/0291—Refrigerant compression by combined gas compression and liquid pumping
-
- 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
- F25J5/00—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
-
- 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
Abstract
The invention provides a system and a method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion. The system comprises a natural gas pipeline, a mixed refrigerant circulating pipeline and a nitrogen refrigeration circulating pipeline, wherein the mixed refrigerant circulating pipeline comprises a refrigerant compressor, a first-stage heat exchanger and a second-stage heat exchanger; the first-stage heat exchanger and the second-stage heat exchanger are connected with the refrigerant compressor; the nitrogen refrigeration circulating pipeline comprises a nitrogen compressor and an overcooling section heat exchanger connected with the nitrogen compressor; the nitrogen refrigeration circulating pipeline is also provided with a nitrogen heat exchanger; and the nitrogen heat exchanger is connected with the mixed refrigerant circulating pipeline and is also connected between the nitrogen compressor and the overcooling section heat exchanger. The method comprises a natural gas treatment process, a mixed refrigerant circulating process and a nitrogen expansion refrigeration process which are simultaneously performed. According to the system and the method provided by the invention, by adding the nitrogen heat exchanger, and enabling the nitrogen heat exchanger to be connected with the mixed refrigerant circulating pipeline and the nitrogen refrigeration circulating pipeline, energy consumption can be effectively reduced.
Description
Technical field
The present invention relates to a kind of natural gas liquefaction system and liquifying method thereof.
Background technology
(FloatingLiquefiedNaturalGas is also known as LNG-FPSO for FLNG, Floating Liquefied Natural Gas device), it is the novel Floating Production device integrating the marine production of liquefied natural gas, storage, handling and outward transport, is applied to the exploitation of offshore gas field and has that cost of investment is low, construction period is short, development risk is little, be easy to migrate and safety high.
Natural gas liquefaction process, core technology as FLNG, to the construction of device, running cost, the safety effects of operation stability and whole system is huge, under the premise meeting Production requirement, the market demand and control cost, it is applied to the liquefaction Technology of Natural Gas of FLNG and the selection of relevant device is most important for the feasibility of reduction investment risk, enhanced scheme.Based on the particular criteria of operation on the sea, owing to cascade type liquefaction process equipment needed thereby quantity is more, compactedness is not high, and the storage capacity of cold-producing medium is relatively big, and thus be accordingly used in offshore natural gas liquefaction has certain difficulty.And mix refrigerant liquefaction process and nitrogen inflation fluid metallization processes seaworthiness are better.The main liquefaction technology being applied to FLNG at present is mix refrigerant liquefaction flow path and nitrogen expansion liquefaction flow path.Mix refrigerant liquefaction flow path process efficiency is high, and power consumption is little, but azeotrope change of component is more sensitive, it is possible to by appropriate design and layout so that it is can adapt to marine special environment, is also the relatively conventional liquefaction flow path of FLNG project.
Summary of the invention
It is an object of the invention to, sum up the feature of existing liquefaction technology, seek design and provide a kind of easy to operate, liquefaction efficiency is high, safety is high, to the natural gas liquefaction process method of large-scale in can be used for, hybrid refrigeration cycle is combined with nitrogen expansion kind of refrigeration cycle formation natural gas liquefaction process.
For achieving the above object, the present invention provides the natural gas liquefaction system of a kind of mix refrigerant pre-cooling nitrogen expansion, including gas pipeline, mixed-refrigerant cycle pipeline and nitrogen refrigerating circulation, wherein:
Described gas pipeline sequentially passes through first stage heat exchanger, second stage heat exchanger and super cooled sect heat exchanger；
Described mixed-refrigerant cycle pipeline includes coolant compressor and the described first stage heat exchanger being connected with described coolant compressor, described second stage heat exchanger；
Described nitrogen refrigerating circulation includes nitrogen compressor and the described super cooled sect heat exchanger being connected with described nitrogen compressor；
It is characterized in that: be additionally provided with nitrogen heat exchanger, it is connected with described mixed-refrigerant cycle pipeline, and it is connected between described nitrogen compressor and described super cooled sect heat exchanger.
The natural gas liquefaction system of described mix refrigerant pre-cooling nitrogen expansion, wherein: described gas pipeline is additionally provided with de-heavy hydrocarbon tower and gas-liquid separator, described de-heavy hydrocarbon tower is arranged between described first stage heat exchanger and described second stage heat exchanger, and described gas-liquid separator is arranged between described second stage heat exchanger and described super cooled sect heat exchanger.
The natural gas liquefaction system of described mix refrigerant pre-cooling nitrogen expansion, wherein: described gas pipeline is being connected to liquid expander after described super cooled sect heat exchanger.
The natural gas liquefaction system of described mix refrigerant pre-cooling nitrogen expansion, wherein: the outlet of described coolant compressor connects described first stage heat exchanger, second stage heat exchanger, connect mix refrigerant J-T valve again, it is divided into two-way from described mix refrigerant J-T valve, wherein a road connects described second stage heat exchanger, another road connects described heat exchanger, and this two-way is back to again the entrance of coolant compressor each through described first stage heat exchanger.
The present invention also provides for the natural gas liquefaction of a kind of mix refrigerant pre-cooling nitrogen expansion, it is characterised in that described method includes the three below process simultaneously carried out:
The processing procedure of natural gas: the natural gas through pretreatment enters first stage heat exchanger, enters back into second stage heat exchanger, subsequently enters super cooled sect heat exchanger, become LNG；
Mixed-refrigerant cycle process: the mix refrigerant under low pressure is after overcompression and cooling, the condensation of part mix refrigerant enters described first stage heat exchanger and described second stage heat exchanger heat exchange and is condensed into liquid after becoming liquid, described second stage heat exchanger is returned then through vaporization after mix refrigerant J-T valve blood pressure lowering and desuperheat, another part cold-producing medium enters nitrogen heat exchanger after described mix refrigerant J-T valve blood pressure lowering and desuperheat, after providing part cold for described nitrogen heat exchanger, the cold-producing medium of above-mentioned two part returns mix refrigerant compressor after finally both passing through described first stage heat exchanger, and the cold-producing medium of natural gas and high pressure is condensed into liquid；
Nitrogen expansion refrigerative circle system: nitrogen compressed and cooling after enter described nitrogen heat exchanger, with the low temperature nitrogen heat exchange returned from described super cooled sect heat exchanger, high pressure nitrogen is lowered the temperature through heat exchange, after entering the decompression cooling of nitrogen expansion machine, enter described super cooled sect heat exchanger, with LNG heat exchange, return again to above-mentioned nitrogen heat exchanger and with high pressure nitrogen heat exchange heat up after return to nitrogen compressor.
The natural gas liquefaction of described mix refrigerant pre-cooling nitrogen expansion, wherein, in the processing procedure of natural gas: the natural gas through first stage heat exchanger heat exchange enters de-heavy hydrocarbon tower, overhead gas enters described second stage heat exchanger and lowers the temperature further, subsequently into gas-liquid separator, liquid-phase reflux after separation is to the tower top of above-mentioned de-heavy hydrocarbon tower, and the gas phase portion after separation enters back into described super cooled sect heat exchanger.
The present invention is by increasing nitrogen heat exchanger, and makes it connect mixed-refrigerant cycle pipeline and nitrogen refrigerating circulation, it is possible to effectively reduce energy consumption.
Specifically, the advantage of this patent is in that:
1. propose the natural gas liquefaction flow process that a kind of mix refrigerant pre-cooling combines with nitrogen expansion refrigeration, compare traditional dinitrogen and expand liquefaction flow path, effectively reduce the energy consumption of liquefaction flow path, the energy consumption of LNG product can be made to be reduced to 0.322kWh/Nm3, it is 0.56kWh/Nm that traditional dinitrogen expands liquefaction flow path energy consumption3；
2. natural QI prostration heavy hydrocarbon overhead gas entrance liquefaction stages heat exchanger is lowered the temperature further, then gas-liquid separation, and liquid phase returns to the backflow of de-heavy hydrocarbon column overhead, and after natural gas liquefaction, pressure reduction adopts liquid expander to recover energy, and reduces liquefaction energy consumption.Decompressor is using J-T valve as standby；
3., in this patent flow process, mix refrigerant precooling process and nitrogen expansion process of refrigerastion are two independent kind of refrigeration cycle, are made up of respective compressor, cooler and heat exchanger；
4. mix refrigerant forms containing methane to the lighter hydrocarbons of pentane, do not contain the component of nitrogen, propane and carbon more than six；
5. nitrogen expansion is by mixed-refrigerant cycle pre-cooling, substantially increases the refrigerating efficiency of nitrogen expansion circulation.And the energy of decompressor output also can, as the energy input of compressor, so be also beneficial to reduce energy consumption further.
Accompanying drawing explanation
Fig. 1 is the structure principle chart of natural gas liquefaction system provided by the invention.
Description of reference numerals:
101 is the natural gas through pretreatment, 102 is the natural gas through first stage heat exchanger 201,202, and 103 is liquid phase, and 104 is the gaseous state mix refrigerant under low pressure, 105 is low temperature nitrogen, and 106 is the mix refrigerant after mix refrigerant J-T valve 209 blood pressure lowering desuperheat；201,202 is first stage heat exchanger, 203 is second stage heat exchanger, and 204 is nitrogen heat exchanger, and 205 is super cooled sect heat exchanger, 206 is de-heavy hydrocarbon tower, 207 is nitrogen expansion machine, and 208 is liquid expander, and 209 is mix refrigerant J-T, 210,211 is mix refrigerant one-level, split-compressor, 212,213,214 is nitrogen one-level, two grades, three-stage blower, and BOG is flash steam, and LNG is liquefied natural gas product；
Detailed description of the invention
Natural gas liquefaction system provided by the invention, its structure and work process as shown in Figure 1:
nullIn the processing procedure of natural gas，Natural gas 101 through pretreatment enters first stage heat exchanger 201、202，Natural gas 102 through heat exchange enters de-heavy hydrocarbon tower 206，Overhead gas enters second stage heat exchanger 203 and lowers the temperature further，Subsequently into gas-liquid separator，Liquid phase 103 after separation is back to the tower top of above-mentioned de-heavy hydrocarbon tower 206，In the process，The natural gas that pressure is 4MPaG (gauge pressure) is liquefied by under the vaporization refrigeration of mix refrigerant in second stage heat exchanger 203，The natural gas of post liquefaction leaves the temperature of second stage heat exchanger 203 and is about-80～-100 DEG C，It enters above-mentioned gas-liquid separator，Gas phase portion enters back into super cooled sect heat exchanger 205 and is cooled to about-150 DEG C，It is decompressed to pressure of storage tank through liquid expander 208，It is cooled to about-155 DEG C；
nullIn mixed-refrigerant cycle process，Mix refrigerant 104 under low pressure is after overcompression and cooling，The condensation of part mix refrigerant enters first stage heat exchanger 201 after becoming liquid、202 and second stage heat exchanger 203 heat exchange be condensed into liquid，Temperature is about-80～-100 DEG C，Second stage heat exchanger 203 is returned then through vaporization after mix refrigerant J-T valve 209 blood pressure lowering and desuperheat，Another part cold-producing medium enters nitrogen heat exchanger 204 after above-mentioned mix refrigerant J-T valve 209 blood pressure lowering and desuperheat，After providing part cold for nitrogen heat exchanger，The cold-producing medium of above-mentioned two part finally both passes through first stage heat exchanger 201、Mix refrigerant stage compressor 210 is returned after 202、Split-compressor 211，And the cold-producing medium of natural gas and high pressure is condensed into liquid respectively；
In nitrogen expansion kind of refrigeration cycle, nitrogen compressed and cooling after enter nitrogen heat exchanger 204, with low temperature nitrogen 105 heat exchange returned from super cooled sect heat exchanger 205, the temperature of low temperature nitrogen about about-93 DEG C, nitrogen heat exchanger 204 introduces part mix refrigerant 106 after mix refrigerant J-T valve 209 blood pressure lowering desuperheat and supplements heat exchange, improve the heat transfer effect between nitrogen；High pressure nitrogen is lowered the temperature through heat exchange, after entering nitrogen expansion machine 207 decompression cooling, enter super cooled sect heat exchanger 205, with LNG heat exchange, LNG is cooled to about-150 DEG C, after returning again to above-mentioned nitrogen heat exchanger 205 and heating up with high pressure nitrogen heat exchange, returns to nitrogen stage compressor 212, split-compressor 212, three-stage blower 213.
It follows that the natural gas liquefaction system of the mix refrigerant pre-cooling nitrogen expansion in the present invention, including gas pipeline, mixed-refrigerant cycle pipeline and nitrogen refrigerating circulation, wherein:
Described gas pipeline sequentially pass through first stage heat exchanger 201,202, second stage heat exchanger 203 and super cooled sect heat exchanger 205；
Described mixed-refrigerant cycle pipeline include coolant compressor 210,211 and connect described first stage heat exchanger 201,202, described second stage heat exchanger 203；
Described nitrogen refrigerating circulation includes nitrogen compressor 212,213,214 and the described super cooled sect heat exchanger 205 connected thereof；
It is mainly characterized by: be additionally provided with nitrogen heat exchanger 204, it is connected with described mixed-refrigerant cycle pipeline, and it is connected between described nitrogen compressor 212,213,214 and described super cooled sect heat exchanger 205, by increasing nitrogen heat exchanger 204, and make it connect mixed-refrigerant cycle pipeline and nitrogen refrigerating circulation, it is possible to effectively reduce energy consumption.
Claims (6)
1. a natural gas liquefaction system for mix refrigerant pre-cooling nitrogen expansion, including gas pipeline, mixed-refrigerant cycle pipeline and nitrogen refrigerating circulation, wherein:
Described gas pipeline sequentially passes through first stage heat exchanger, second stage heat exchanger and super cooled sect heat exchanger；
Described mixed-refrigerant cycle pipeline includes coolant compressor and the described first stage heat exchanger being connected with described coolant compressor, described second stage heat exchanger；
Described nitrogen refrigerating circulation includes nitrogen compressor and the described super cooled sect heat exchanger being connected with described nitrogen compressor；
It is characterized in that: be additionally provided with nitrogen heat exchanger, it is connected with described mixed-refrigerant cycle pipeline, and it is connected between described nitrogen compressor and described super cooled sect heat exchanger.
2. the natural gas liquefaction system of mix refrigerant pre-cooling nitrogen expansion according to claim 1, it is characterized in that: described gas pipeline is additionally provided with de-heavy hydrocarbon tower and gas-liquid separator, described de-heavy hydrocarbon tower is arranged between described first stage heat exchanger and described second stage heat exchanger, and described gas-liquid separator is arranged between described second stage heat exchanger and described super cooled sect heat exchanger.
3. the natural gas liquefaction system of mix refrigerant pre-cooling nitrogen expansion according to claim 1, it is characterised in that: described gas pipeline is being connected to liquid expander after described super cooled sect heat exchanger.
4. the natural gas liquefaction system of mix refrigerant pre-cooling nitrogen expansion according to claim 1, it is characterized in that: the outlet of described coolant compressor connects described first stage heat exchanger, second stage heat exchanger, connect mix refrigerant J-T valve again, it is divided into two-way from described mix refrigerant J-T valve, wherein a road connects described second stage heat exchanger, another road connects described heat exchanger, and this two-way is back to again the entrance of coolant compressor each through described first stage heat exchanger.
5. the natural gas liquefaction of a mix refrigerant pre-cooling nitrogen expansion, it is characterised in that described method includes the three below process simultaneously carried out:
The processing procedure of natural gas: the natural gas through pretreatment enters first stage heat exchanger, enters back into second stage heat exchanger, subsequently enters super cooled sect heat exchanger, become LNG；
Mixed-refrigerant cycle process: the mix refrigerant under low pressure is after overcompression and cooling, the condensation of part mix refrigerant enters described first stage heat exchanger and described second stage heat exchanger heat exchange and is condensed into liquid after becoming liquid, described second stage heat exchanger is returned then through vaporization after mix refrigerant J-T valve blood pressure lowering and desuperheat, another part cold-producing medium enters nitrogen heat exchanger after described mix refrigerant J-T valve blood pressure lowering and desuperheat, after providing part cold for described nitrogen heat exchanger, the cold-producing medium of above-mentioned two part returns mix refrigerant compressor after finally both passing through described first stage heat exchanger, and the cold-producing medium of natural gas and high pressure is condensed into liquid；
Nitrogen expansion refrigerative circle system: nitrogen compressed and cooling after enter described nitrogen heat exchanger, with the low temperature nitrogen heat exchange returned from described super cooled sect heat exchanger, high pressure nitrogen is lowered the temperature through heat exchange, after entering the decompression cooling of nitrogen expansion machine, enter described super cooled sect heat exchanger, with LNG heat exchange, return again to above-mentioned nitrogen heat exchanger and with high pressure nitrogen heat exchange heat up after return to nitrogen compressor.
6. the natural gas liquefaction of mix refrigerant pre-cooling nitrogen expansion according to claim 5, it is characterized in that, in the processing procedure of natural gas: the natural gas through first stage heat exchanger heat exchange enters de-heavy hydrocarbon tower, overhead gas enters described second stage heat exchanger and lowers the temperature further, subsequently into gas-liquid separator, liquid-phase reflux after separation is to the tower top of above-mentioned de-heavy hydrocarbon tower, and the gas phase portion after separation enters back into described super cooled sect heat exchanger.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610244448.7A CN105737516A (en) | 2016-04-18 | 2016-04-18 | System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610244448.7A CN105737516A (en) | 2016-04-18 | 2016-04-18 | System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105737516A true CN105737516A (en) | 2016-07-06 |
Family
ID=56254743
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610244448.7A Pending CN105737516A (en) | 2016-04-18 | 2016-04-18 | System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105737516A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106440656A (en) * | 2016-11-02 | 2017-02-22 | 中国寰球工程有限公司 | Natural gas liquefying system for carbon dioxide precooling double-stage nitrogen expansion |
| CN112304026A (en) * | 2020-11-03 | 2021-02-02 | 江苏科技大学 | Crude oil volatile gas grading liquefaction system and working method thereof |
| CN112556446A (en) * | 2020-12-08 | 2021-03-26 | 江苏科技大学 | Oil gas condensation recovery system of crude oil tanker and working method thereof |
| CN113108549A (en) * | 2021-04-23 | 2021-07-13 | 吉林大学 | Offshore natural gas liquefaction system integrating nitrogen expansion cycle with mixed refrigerant |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL113348C (en) * | 1959-10-23 | 1966-11-15 | ||
| US3780535A (en) * | 1970-12-21 | 1973-12-25 | Air Liquide Sa Etude Exploit P | Method of cooling a gaseous mixture and installation therefor |
| CN101223410A (en) * | 2005-06-23 | 2008-07-16 | 林德股份公司 | Method for liquefying a hydrocarbon-rich flow |
| WO2009130466A2 (en) * | 2008-04-23 | 2009-10-29 | Statoilhydro Asa | Dual nitrogen expansion process |
| CN101948706A (en) * | 2010-08-18 | 2011-01-19 | 中国海洋石油总公司 | Mixed refrigerant and nitrogen expansion combinational refrigeration type natural gas liquefying method |
| CN102564059A (en) * | 2012-02-19 | 2012-07-11 | 中国石油集团工程设计有限责任公司 | Twin-stage multi-component mixed refrigerant refrigeration natural gas liquefaction system and method |
| CN105371590A (en) * | 2014-09-02 | 2016-03-02 | 李均伦 | Full-cooling-capacity-recovery natural gas liquefaction process with precooling and mixed refrigeration |
| CN205718201U (en) * | 2016-04-18 | 2016-11-23 | 中国寰球工程公司 | The natural gas liquefaction system of mix refrigerant pre-cooling nitrogen expansion |
-
2016
- 2016-04-18 CN CN201610244448.7A patent/CN105737516A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL113348C (en) * | 1959-10-23 | 1966-11-15 | ||
| US3780535A (en) * | 1970-12-21 | 1973-12-25 | Air Liquide Sa Etude Exploit P | Method of cooling a gaseous mixture and installation therefor |
| CN101223410A (en) * | 2005-06-23 | 2008-07-16 | 林德股份公司 | Method for liquefying a hydrocarbon-rich flow |
| WO2009130466A2 (en) * | 2008-04-23 | 2009-10-29 | Statoilhydro Asa | Dual nitrogen expansion process |
| CN101948706A (en) * | 2010-08-18 | 2011-01-19 | 中国海洋石油总公司 | Mixed refrigerant and nitrogen expansion combinational refrigeration type natural gas liquefying method |
| CN102564059A (en) * | 2012-02-19 | 2012-07-11 | 中国石油集团工程设计有限责任公司 | Twin-stage multi-component mixed refrigerant refrigeration natural gas liquefaction system and method |
| CN105371590A (en) * | 2014-09-02 | 2016-03-02 | 李均伦 | Full-cooling-capacity-recovery natural gas liquefaction process with precooling and mixed refrigeration |
| CN205718201U (en) * | 2016-04-18 | 2016-11-23 | 中国寰球工程公司 | The natural gas liquefaction system of mix refrigerant pre-cooling nitrogen expansion |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106440656A (en) * | 2016-11-02 | 2017-02-22 | 中国寰球工程有限公司 | Natural gas liquefying system for carbon dioxide precooling double-stage nitrogen expansion |
| CN106440656B (en) * | 2016-11-02 | 2022-02-15 | 中国寰球工程有限公司 | Carbon dioxide precooling two-stage nitrogen expansion natural gas liquefaction system |
| CN112304026A (en) * | 2020-11-03 | 2021-02-02 | 江苏科技大学 | Crude oil volatile gas grading liquefaction system and working method thereof |
| CN112556446A (en) * | 2020-12-08 | 2021-03-26 | 江苏科技大学 | Oil gas condensation recovery system of crude oil tanker and working method thereof |
| CN112556446B (en) * | 2020-12-08 | 2022-08-19 | 江苏科技大学 | Oil gas condensation recovery system of crude oil tanker and working method thereof |
| CN113108549A (en) * | 2021-04-23 | 2021-07-13 | 吉林大学 | Offshore natural gas liquefaction system integrating nitrogen expansion cycle with mixed refrigerant |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2021201534B2 (en) | Pre-cooling of natural gas by high pressure compression and expansion | |
| CN101948706B (en) | Mixed refrigerant and nitrogen expansion combinational refrigeration type natural gas liquefying method | |
| KR101677306B1 (en) | Method for producing a stream of subcooled liquefied natural gas using a natural gas feedstream, and associated facility | |
| US20030177785A1 (en) | Process for producing a pressurized liquefied gas product by cooling and expansion of a gas stream in the supercritical state | |
| EA006724B1 (en) | Process for producing liquid natural gas (variants) | |
| CN101711335A (en) | Method and system for producing LNG | |
| WO2017121042A1 (en) | Method and apparatus for liquefying methane-rich gas through expansion refrigeration | |
| CN101893367A (en) | Method for liquefying natural gas by using mixed coolant | |
| CN101137878A (en) | System and method for cooling a bog stream | |
| Xiong et al. | Integration of CO2 cryogenic removal with a natural gas pressurized liquefaction process using gas expansion refrigeration | |
| WO2013135037A1 (en) | Apparatus and method for liquefying natural gas by refrigerating single mixed working medium | |
| WO2013071789A1 (en) | Device and method for liquefying natural gas using single mixed working medium as refrigeration medium | |
| CN105737516A (en) | System and method for liquefying natural gas by mixed refrigerant precooling and nitrogen expansion | |
| US9835373B2 (en) | Integrated cascade process for vaporization and recovery of residual LNG in a floating tank application | |
| CN102538390B (en) | Novel natural gas liquefaction system and natural gas liquefaction method | |
| CN104913593B (en) | A kind of liquefied technique of BOG and device | |
| JP2017207273A (en) | Liquefaction method and system | |
| CN216620451U (en) | LNG reforming hydrogen production and LNG cold energy liquefied hydrogen integrated system | |
| CN104019626B (en) | The cold method and device preparing liquefied natural gas of a kind of azeotrope two-stage system | |
| CN105605883A (en) | Oxygen-bearing coalbed methane liquefaction separation system and technique | |
| CN103868324B (en) | The natural gas liquefaction of small-sized skid-mounted type mix refrigerant and NGL reclaim integrated system | |
| CN103175380B (en) | Low concentration coal-bed gas produces LNG device containing oxygen cryogenic liquefying | |
| CN104807287A (en) | Small natural gas liquefaction and refrigeration system and small natural gas liquefaction and refrigeration method | |
| CN102628634B (en) | Ternary-cycle cascade refrigeration natural gas liquefaction system and method thereof | |
| CN203310202U (en) | Dual-mixed-refrigerant liquefying system applied to base load type natural gas liquefaction factory |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20160706 |