CN106123484A - Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure - Google Patents
Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure Download PDFInfo
- Publication number
- CN106123484A CN106123484A CN201510231972.6A CN201510231972A CN106123484A CN 106123484 A CN106123484 A CN 106123484A CN 201510231972 A CN201510231972 A CN 201510231972A CN 106123484 A CN106123484 A CN 106123484A
- Authority
- CN
- China
- Prior art keywords
- throttling
- outlet
- import
- gas
- bobbin carriage
- 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
Landscapes
- Separation By Low-Temperature Treatments (AREA)
Abstract
The invention belongs to natural gas in low temperature liquefaction technology field, relate to LNG tri-grade low-temp cold plate fin heat exchanger and mix refrigerant Refrigeration Technique, apply N2-CH46.0MPa ,-120 DEG C of natural gass are cooled to-164 DEG C and liquefy in three stream plate-fin heat exchanger by mix refrigerant, in order to LNG crosses iced storage and convenient transport；Application plate-fin heat exchanger first pre-cooling non-azeotrope N that liquefies2-CH4Mix refrigerant, N2-CH4Throttle again after liquefaction to mix refrigerant side cooling from two grades the natural gas that outlet temperature is-120 DEG C, N2-CH4Mix refrigerant, makes natural gas side natural gas and N2-CH4Side mix refrigerant is all liquefied, and reaches pre-cooling and natural gas in low temperature liquefaction purpose before mix refrigerant throttling；Its compact conformation, heat exchange efficiency is high, can be used for land LNG and FLNG field, ocean, it is achieved-120 DEG C～-164 DEG C of natural gas in low temperature liquefaction process, solves a LNG three tier structure refrigeration technique difficult problem.
Description
Technical field
The invention belongs to natural gas in low temperature liquefaction technology field, relate to LNG tri-grade low-temp cold plate fin heat exchanger and mix refrigerant Refrigeration Technique, apply N2—CH46.0MPa ,-120 DEG C of natural gass are cooled to-164 DEG C and liquefy in three stream plate-fin heat exchanger by mix refrigerant, in order to LNG crosses iced storage and convenient transport；Application plate-fin heat exchanger first pre-cooling non-azeotrope N that liquefies2—CH4Mix refrigerant, N2—CH4Throttle again after liquefaction to mix refrigerant side cooling from two grades the natural gas that outlet temperature is-120 DEG C, N2—CH4Mix refrigerant, makes natural gas side natural gas and N2—CH4Side mix refrigerant is all liquefied, and reaches pre-cooling and natural gas in low temperature liquefaction purpose before mix refrigerant throttling；Its compact conformation, heat exchange efficiency is high, can be used for land LNG and FLNG field, ocean, it is achieved-120 DEG C～-164 DEG C of natural gas in low temperature liquefaction process, solves a LNG three tier structure refrigeration technique difficult problem.
Background technology
Large-scale mix refrigerant natural gas liquefaction flow process mainly includes three phases, first stage is that the natural gas after compressing carries out pre-cooling,-53 DEG C will be cooled in advance by 36 DEG C of natural gass, second stage is that from-53 DEG C, natural gas is cooled to-120 DEG C, prepare for low-temperature liquefaction, three phases is-120 DEG C of natural gass to be cooled to-164 DEG C and liquefies, and three processes can use different refrigeration process, different cold-producing medium and various heat exchange equipment.At present, mix refrigerant natural gas liquefaction system uses overall heat exchange mode mostly, and three sections of process of refrigerastions are connected as an entirety, and heat exchanger height is up to 60～80 meters, heat exchange efficiency is improved significantly, but it is the most complicated to there is problems of heat-exchanging process flow process, heat transmission equipment volume is the hugest, brings serious inconvenience to processing and manufacturing, in-site installation and transport, and the problems such as pipe leakage once occur, being difficult to detect, it is easy to cause whole heat exchanger to scrap, set technique equipment stops production.Further, since common tubular heat exchanger uses tube sheet to connect bundle of parallel tubes mode, simple in construction, self-constriction ability is poor, generally the heat exchange of sub-thread stream, and heat exchange efficiency is relatively low, and volume is relatively big, and the temperature difference is less, it is difficult to is cooled down in a flow process by natural gas and liquefies.In addition, with the Large LNG liquefaction system that spiral winding tube type heat exchanger is main liquefaction device, also there is the feature of syllogic mix refrigerant refrigeration, plus wrap-round tubular heat exchanger, there is function that self-tightening shrinks and the advantage such as heat exchange area per unit volume is big, it is applicable to Large LNG low-temperature liquefaction environment, there is the highest liquefaction efficiency and economy, apply in general to produce daily the LNG system of 100 ten thousand to 500 ten thousand sides.Owing to natural gas liquefaction system is limited by source of the gas yield, the daily output in most of middle-size and small-size gas fields is many between 60 ten thousand to 100 ten thousand sides, as the most uneconomical in the liquefaction system using large-scale wrap-round tubular heat exchanger, and processing and manufacturing cost and investment are the biggest.Plate-fin heat exchanger has the highest heat exchange efficiency equally relative to wrap-round tubular heat exchanger, after many employing high-strength aluminum alloy materials, heat conductivity is big, heat exchange area per unit volume is big, and overall height is equivalent to 1/3rd of wrap-round tubular heat exchanger, overall heat exchanger size is less, without tube sheet, heat exchanger self-tightening under worst cold case shrinks and requires less, that the yield that is particularly well-suited between 60 ten thousand to 100 ten thousand sides is less LNG liquefaction system.In recent years, development along with the floating LNG liquefaction vessel in marine field, typically sea bed exploitation natural gas straight out is connected on floating FLNG liquefaction vessel liquefaction, owing to being rocked by LNG liquefaction vessel and space is little etc. that problem is affected, main liquefaction heat exchanger should not be the highest, as used higher wrap-round tubular heat exchanger as main liquefaction device, even if it the most also can have a strong impact on LNG ship in deepwater stability after segmentation, and plate-fin heat exchanger has relatively low overall height compared with wrap-round tubular heat exchanger under identical yield, after freezing such as re-segmenting, it is more suitable for the systems such as the Floating Liquefied ship of FLNG.Present invention is generally directed to the land LNG between 60 ten thousand to 100 ten thousand sides and ocean FLNG liquefaction system, according to LNG tri-grade low-temp liquefaction feature, using three sections of respective independent plate-fin heat exchangers as main heat transmission equipment, segmentation independent cooling, emphasis is for second level N2—CH4Mix refrigerant refrigeration process flow process, research and develop warm area third level refrigeration process technology between-120 DEG C～-164 DEG C and equipment, solve third level natural gas in low temperature liquefaction Key technique problem, the i.e. cold three stream plate-fin heat exchanger structures of LNG low-temperature liquefaction three tier structure and technological process problem.
Summary of the invention
Present invention is generally directed to three grades-120 DEG C～-164 DEG C refrigeration problems of natural gas, use and there are volume is little, heat exchange efficiency is high, heat transfer temperature difference is big three stream plate-fin heat exchanger as main heat exchange equipment, apply N2—CH4The refrigeration process flow process of throttling after the pre-cooling of cold-producing medium elder generation, controls freezing by change of state flow process, and then controls natural gas precooling temperature and pressure, improve heat exchange efficiency, solve three grades of pre-cooling problems of natural gas.
The technical solution of the present invention:
Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure, including N after Imported gas flange 1, Imported gas adapter 2, Imported gas bobbin carriage 3, throttling2—CH4N after outlet(discharge) flange 4, throttling2—CH4N after discharge connection 5, throttling2—CH4N after outlet bobbin carriage 6, throttling2—CH4Outlet deflector 7, flap 8, left strip of paper used for sealing 9, lower strip of paper used for sealing 10, N2—CH4Outlet bobbin carriage 11, N2—CH4Export N after U-shaped adapter 12, choke valve 13, gas outlet flange 14, gas outlet adapter 15, gas outlet bobbin carriage 16, throttling2—CH4N after suction flange 17, throttling2—CH4N after entrance sleeve 18, throttling2—CH4N after import bobbin carriage 19, throttling2—CH4Import deflector 20, right strip of paper used for sealing 21, upper strip of paper used for sealing 22, N2—CH4Suction flange 23, N2—CH4Entrance sleeve 24, N2—CH4Import bobbin carriage 25, Imported gas deflector 26, gas outlet deflector 27, N2—CH4Import deflector 28, N2—CH4Outlet deflector 29, dividing plate 30, front panel 31, rear board 32；Described choke valve 13, including the conical surface the first sealing ring 33, the conical surface the second sealing ring 34, choke valve valve seat 35, throttle valve spring 36, clip 37, pin rod 38, choke valve valve gap 39, housing screw 40, spring the first packing ring 41, spring the second packing ring 42, throttle valve stem 43, choke valve valve body 44；It is characterized in that: the most alternate between front panel 31 with rear board 32 be connected flap 8 and dividing plate 30；Flap 8 top is sequentially connected with N after throttling2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4Import deflector 28, and formed organize connection more；Flap 8 bottom is sequentially connected with N after throttling2—CH4Import deflector 20, gas outlet deflector 27, N2—CH4Export deflector 29, and connection is organized in formation more；Left strip of paper used for sealing 9 is sequentially connected on the left of heat exchanger between dividing plate 30；Right strip of paper used for sealing 21 is sequentially connected between heat exchanger right side partition 30；Upper strip of paper used for sealing 21 is sequentially connected on the upside of heat exchanger between dividing plate 30, and has each fluid streams access way successively；Lower strip of paper used for sealing 10 is sequentially connected on the downside of heat exchanger between dividing plate 30, and has each fluid streams access way successively；N after throttling2—CH4N after exit passageway and throttling2—CH4Intake channel is positioned at same layer, and forms N after throttling2—CH4Side interlayer；Imported gas passage and gas exit passageway are positioned at same layer, and form natural gas side interlayer；N2—CH4Intake channel and N2—CH4Exit passageway is positioned at same layer, and forms N2—CH4Side interlayer；N after throttling2—CH4Side interlayer, natural gas side interlayer, N2—CH4Side interlayer is arranged in order one group of interlayer of formation, and many group interlayers are arranged in order composition overall heat exchange device；Often N after the throttling in group interlayer2—CH4Outlet, Imported gas, N2—CH4Three row are lined up in import successively at heat exchanger top, and sequentially form N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Import arranges；N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Import row top connects N after the throttling of semicircle column type the most respectively2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH4Import bobbin carriage 25；N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Bottom import row, each mouth connects N after throttling the most respectively2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4Import deflector 28；N after throttling2—CH4—C2H4Outlet deflector 7, Imported gas deflector 26, N2—CH4Flap 8 top in each interlayer is connected the most respectively bottom import deflector 28；N after throttling2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH425 3 bobbin carriages of import bobbin carriage are arranged in order and are connected to heat exchanger top；N after throttling2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH4Import bobbin carriage 25 top connects N after throttling respectively2—CH4Discharge connection 5, Imported gas adapter 2, N2—CH4Entrance sleeve 24；N after throttling2—CH4Discharge connection 5, Imported gas adapter 2, N2—CH4Entrance sleeve 24 top connects N after throttling respectively2—CH4Outlet(discharge) flange 4, Imported gas flange 1, N2—CH4Suction flange 23；The often N in group interlayer2—CH4N after outlet, gas outlet, throttling2—CH4Import lines up three row successively at exchanger base, and sequentially forms N2—CH4N after outlet row, gas outlet row, throttling2—CH4Import arranges；N2—CH4N after outlet row, gas outlet row, throttling2—CH4Semicircle column type N is connected the most respectively bottom import row2—CH4N after outlet bobbin carriage 11, gas outlet bobbin carriage 16, throttling2—CH4Import bobbin carriage 19；N2—CH4N after outlet row, gas outlet row, throttling2—CH4Import row top connects N the most respectively2—CH4N after outlet deflector 29, gas outlet deflector 27, throttling2—CH4Import deflector 20；N2—CH4N after outlet deflector 29, gas outlet deflector 27, throttling2—CH4Import deflector 20 top connects in each interlayer bottom flap 8 the most respectively；N2—CH4N after outlet bobbin carriage 11, gas outlet bobbin carriage 16, throttling2—CH419 3 bobbin carriages of import bobbin carriage are arranged in order and are connected to exchanger base；N after gas outlet bobbin carriage 16, throttling2—CH4Gas outlet is connected respectively by N after pipe 15, throttling bottom import bobbin carriage 192—CH4Entrance sleeve 18；Gas outlet presses N after pipe 15, throttling2—CH4N after gas outlet flange 14, throttling is connected respectively bottom entrance sleeve 182—CH4Suction flange 17；N2—CH4N is connected bottom outlet bobbin carriage 112—CH4Export U-shaped adapter 12；N2—CH4Export and on the right side of U-shaped adapter 12, connect N after throttling2—CH4Import bobbin carriage 19, choke valve 13 is installed at middle part；Threaded choke valve valve gap 39 on the right side of throttle valve stem 43；Choke valve valve gap 39 is installed in choke valve valve seat 35；Choke valve valve seat 35 connects throttling valve body 44 by housing screw 40；Pin rod 48 is through choke valve valve gap 39 and throttle valve stem 43；Clip 37 is installed in choke valve valve gap 39 draw-in groove；Throttle valve spring 36 is installed in choke valve valve gap 39 and choke valve valve seat 35, and center is throttle valve stem 43, and right side contacts with spring the first packing ring 41, and left side contacts with spring the second packing ring 42；On the left of throttle valve spring 36 pretension throttle valve stem 43, on the left of the spool conical surface and choke valve valve body 44, diffusion cover inner surface forms sealing surface；The conical surface the first sealing ring 33, the conical surface the second sealing ring 34 are installed on the left of throttle valve stem 43 in spool conical surface seal groove the most successively.
The horizontal section of flap 8 is zigzag, generally long side shape aluminium alloy flap；Dividing plate 30, front panel 31, rear board 32 are cuboid aluminium alloy sheet；Flap 8 intersects successively and is installed between dividing plate 30, opening upwards；N after throttling2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4The horizontal section of import deflector 28 is zigzag, and upper and lower two ends horizontal section sawtooth height is identical, and upper and lower two ends horizontal section sawtooth length is different, and top section sawtooth length is less than bottom section sawtooth length；N after throttling2—CH4Import deflector 20, gas outlet deflector 27, N2—CH4The outlet horizontal section of deflector 29 is zigzag, and upper and lower two ends horizontal section sawtooth height is identical, and upper and lower two ends horizontal section sawtooth length is different；Top section sawtooth length is more than bottom section sawtooth length.
Application N2—CH46.0MPa ,-120 DEG C of natural gass are cooled to-164 DEG C and liquefy in three stream plate-fin heat exchanger by mix refrigerant, in order to LNG crosses iced storage and convenient transport；Application plate-fin heat exchanger first pre-cooling non-azeotrope N that liquefies2—CH4Mix refrigerant, N2—CH4Throttle again after liquefaction to mix refrigerant side cooling from two grades the natural gas that outlet temperature is-120 DEG C, N2—CH4Mix refrigerant, makes natural gas side natural gas and N2—CH4Side mix refrigerant is all liquefied, and reaches pre-cooling and natural gas in low temperature liquefaction purpose before mix refrigerant throttling.
Supplement mix refrigerant by N after throttling2—CH4Entrance sleeve 18 fills into.
N2—CH4N is entered when-120 DEG C and 1.58MPa2—CH4Import bobbin carriage 25, at N2—CH4It is allocated in N in import bobbin carriage 252—CH4Import arranges each import, is entered back into by each import and often organizes the N in interlayer2—CH4Side interlayer, the N after being throttled2—CH4Mix refrigerant pre-cooling is liquefied, then through N2—CH4Outlet arranges each outlet and flow to N2—CH4Outlet bobbin carriage 11, temperature is reduced to-164 DEG C, pressure drop as little as 1.38MPa, then through being installed on N2—CH4Exporting the choke valve throttling in U-shaped adapter 12, pressure drop as little as 0.3MPa after throttling, after throttling, nitrogen temperature becomes-185 DEG C, being in gas-liquid two-phase state, after throttling, methane temperature becomes-163.5 DEG C, is in undercooling state, after throttling, mix refrigerant is gas-liquid two-phase, then through N2—CH4Export U-shaped adapter 12 and enter N after throttling2—CH4Import bobbin carriage 19, N after throttling2—CH4Import arranges N after the throttling in each import entrance often group interlayer2—CH4Side interlayer, flows up cooling N2—CH4After side interlayer, natural gas side interlayer ,-130 DEG C, 0.3MPa time, through throttling after N2—CH4Outlet arranges each outlet, enters N after throttling2—CH4Outlet bobbin carriage 6 converges, then N after throttling2—CH4Discharge connection 5 flows out three tier structure cold drawing fin heat exchanger and enters two-stage system cold drawing fin heat exchanger.
Natural gas-120 DEG C, 5.5MPa time enter Imported gas bobbin carriage 3, be allocated in Imported gas bobbin carriage 3 Imported gas arrange each import, by each import enter back into often group interlayer in natural gas side interlayer, be throttled rear N2—CH4Mix refrigerant pre-cooling in the interlayer of side, after pre-cooling temperature be reduced to-164 DEG C, pressure drop as little as 5.3MPa time liquefaction, it flow to gas outlet bobbin carriage 16 through gas outlet row after liquefaction, then flow out three tier structure device for cooling through gas outlet adapter 15, after reducing pressure by regulating flow, send into LNG basin.
During choke valve work, N2—CH4Circular passage between choke valve valve seat 35 and choke valve valve body 44 is entered from choke valve valve seat 35 top, right side through hole, and act on throttle valve stem 43 conical seal (contact) face, when pressure sets preload pressure more than throttle valve spring 36, promote throttle valve stem 43, driving choke valve valve gap 39 to left movement, choke valve is opened and throttling refrigerant.Choke valve sets pressure and can set according to system design temperature, being regulated by throttle valve spring 36 pretightning force between choke valve valve gap 39 and throttle valve stem 43, pretightning force is by rotary barrel throttle valve gap 39 and changes the method for throttle valve spring 36 pretension height and realizes throttling refrigeration；Choke valve must carry out throttling test between installing and accurately regulate, and the satisfied throttling of regulation is installed on N after requiring2—CH4Export U-shaped adapter 12 and manage interior.
Principle Problems involved by scheme:
First, traditional LNG mix refrigerant natural gas liquefaction system uses overall heat exchange mode, heat exchange efficiency relatively tandem type LNG liquefaction system is significantly improved, heat exchanger quantity is made to reduce, overall LNG Lquified Process Flow is simplified, the refrigeration system of independent operating reduces, convenient management, but after there is problems of LNG Lquified Process Flow simplification, make LNG main heat exchanger bulky, heat-exchanging process is complicated, processing and manufacturing, in-site installation and transport difficulty increase, and the problems such as pipe leakage once occur, it is difficult to detect, easily cause whole heat exchanger to scrap, set technique equipment stops production.For solving this problem, natural gas temperature change procedure in main heat exchanger is divided into 36 DEG C～-53 DEG C ,-53 DEG C～-120 DEG C by the present invention,-120 DEG C～-164 DEG C of three ranks, use three independent heat exchangers, complete three temperature ranges heat transfer process from high to low, primary study is developed-120 DEG C～-164 DEG C low-temperature heat exchange flow processs of the third level and third level plate-fin heat exchanger population structure and imports and exports parameter, and uses N2—CH4Chiller refrigeration technique, solves the 3rd section of cooling heat exchange plant issue.Research process is relatively independent, can be connected to become entirety with first two sections, consistent with integrated main heat exchange heat exchange principle after connection, it is simple to transports and installs after main heat exchanger partition.Secondly, N is used2—CH4After chiller refrigeration technique, must be to N before throttling2—CH4Carry out supercool.Cryogen import be 1.58MPa ,-120 DEG C time, N2—CH4In mix refrigerant, methane has been liquefied, and nitrogen is the most saturated, is in gas phase state, when pressure reach 1.38MPa, precooling temperature reach-164 DEG C time, nitrogen reaches saturated and is liquefied, the available bigger refrigerating capacity of throttling again after liquefaction.Precooling process is carried out with natural gas liquefaction and subcooling process simultaneously, so, three stream plate-fin heat exchanger low-temperature heat exchanges must be used.N2—CH4Mix refrigerant is mainly used in the cold process of three tier structure, must be through-53 DEG C～-120 DEG C ,-120 DEG C～-164 DEG C of two sections of low temperature precooling process, during two-stage system is cold, N before throttling2—CH4Mix refrigerant precooling process and natural gas liquefaction and C2H4Subcooling process is carried out simultaneously.Traditional tubular heat exchanger connects bundle of parallel tubes structure owing to have employed two pieces of large tubesheets, volume is bigger, heat transfer temperature difference is less, easily subregion, tube pitch is relatively big, and self-constriction ability is poor, apply in general to sub-thread stream heat exchange, heat exchange efficiency is relatively low, it is difficult to is cooled down in a flow process by natural gas and liquefies, and is not readily accomplished multiple flow uniform heat exchange process.The present invention develops high-strength aluminum alloy three stream plate-fin heat exchanger that can bear 6.4MPa pressure, low temperature-185 DEG C, can complete bifilar stream heat transfer process under high pressure low temperature operating mode.Use non-azeotrope N2—CH4After mix refrigerant, after can making saturated liquid nitrogen throttling, cryogen inlet temperature reaches-185 DEG C, produces enough heat transfer temperature difference motive forces.Simultaneously, methane throttles to-163.5 DEG C of supercooled states under supercooled state, its sensible heat can be continued with, reach re-evaporation during saturation temperature-146 DEG C, three grades of liquefaction process are made to have three low-temperature heat exchange temperature, including two evaporating temperatures, reduce diabatic process entropy production with this, reduce diabatic process loss.Additionally, apply in general to the large-scale natural gas liquefaction system of side's every day 100 ten thousand to 500 ten thousand with the Large LNG liquefaction system that wrap-round tubular heat exchanger is main liquefaction device.When yield is between 60 ten thousand to 100 ten thousand sides, plate-fin heat exchanger has the highest heat exchange efficiency equally relative to wrap-round tubular heat exchanger, after many employing high-strength aluminum alloy materials, heat conductivity is big, heat exchange area per unit volume is big, and overall height is equivalent to 1/3rd of wrap-round tubular heat exchanger, without tube sheet, it is less that heat exchanger self-tightening under worst cold case shrinks requirement, is particularly well-suited to the LNG liquefaction system that yield is less.In recent years, development along with the floating LNG liquefaction vessel in marine field, typically sea bed exploitation natural gas straight out is connected on floating LNG liquefaction vessel liquefaction, owing to being rocked by LNG liquefaction vessel and space is little etc. that problem is affected, main liquefaction heat exchanger should not be the highest, as used higher wrap-round tubular heat exchanger as main liquefaction device, even if it the most also can have a strong impact on LNG ship in deepwater stability after segmentation, and plate-fin heat exchanger has relatively low overall height compared with wrap-round tubular heat exchanger under identical yield, after dividing three sections to process again, can effectively reduce heat exchanger height, it is not only applicable to the natural gas liquefaction system between the side of land 60 ten thousand to 100 ten thousand, it is more suitable for the systems such as floating LNG liquefaction vessel.
The technical characterstic of the present invention:
Present invention is generally directed to cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure between side's every day 60 ten thousand to 100 ten thousand, use and there are volume is little, heat exchange efficiency is high, heat transfer temperature difference is big three stream plate-fin heat exchanger as main heat exchange equipment, apply N2—CH4The refrigeration process flow process of throttling refrigeration after first pre-cooling, solves the cold problem of three tier structure that natural gas is at-120 DEG C～-164 DEG C；The cold process of three tier structure has compact conformation by three stream plate-fin heat exchanger, medium band phase-change heat transfer, heat transfer coefficient is big, it is possible to resolve three grades of mix refrigerant pre-coolings of natural gas, a natural gas in low temperature liquefaction technology difficult problem during Large LNG low-temperature liquefaction, improves system heat exchange and liquefaction efficiency；After applying three grades of LNG low-temperature liquefaction processes, LNG main heat exchanger can be divided into three independent heat exchangers, and volume reduces, sectional is processed manufacturing, transporting and in-site installation, the problems such as pipe leakage once there is, it is easy to detection, do not easily cause whole heat exchanger and scrap and set technique equipment stopping production；Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure can reasonable distribution liquefaction stages and the thermic load of super cooled sect, make that liquefaction stages is relative with super cooled sect to be coordinated, can ensure that uniformly and intensity meets design requirement to winding process theoretically in conjunction with the load distribution of large heat exchanger and heat exchanger tube strength characteristics；Rationally have selected heat exchanger inlet and outlet position and material, heat exchanger structure can be made compacter, heat transfer process is optimized；Owing to being medium band phase-change heat-exchange process, pressure reduction between different medium and the temperature difference are limited requirement less, process units operation easier reduces, safety is improved, can be used for land LNG and FLNG field, ocean, realize-120 DEG C～-164 DEG C of natural gas in low temperature precooling process, solve a LNG three tier structure refrigeration technique difficult problem.Additionally, built in pipeline throttling refrigeration technology is applied to N by three tier structure cold drawing fin heat exchanger2—CH4Throttling refrigeration process, makes three grades of plate-fin heat exchangers have effect of throttling refrigeration after first pre-cooling, can obtain three grades-120 DEG C～-164 DEG C of natural gas liquefactions refrigeration intervals, meet LNG low-temperature liquefaction temperature requirement.
Accompanying drawing explanation
Fig. 1 be cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure throttling after N2—CH4Side plate wing manifold figure.
Fig. 2 is the natural gas side plate wing manifold figure of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure.
Fig. 3 is the N of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure2—CH4Side plate wing manifold figure.
Fig. 4 is the top strip of paper used for sealing of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure and imports and exports under row regarding schematic diagram.
Fig. 5 is the bottom seal of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure and imports and exports row upper schematic diagram.
Fig. 6 is flap and the dividing plate alternate row plate schematic diagram of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure.
Fig. 7 is the throttle-valve structure figure of cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure.
Detailed description of the invention
By N2—CH4N is squeezed into when-120 DEG C and 1.58MPa2—CH4Import bobbin carriage 25, at N2—CH4It is allocated in N in import bobbin carriage 252—CH4Import arranges each import, is entered back into by each import and often organizes the N in interlayer2—CH4Side interlayer, the N after being throttled2—CH4Mix refrigerant pre-cooling is liquefied, then through N2—CH4Outlet arranges each outlet and flow to N2—CH4Outlet bobbin carriage 11, temperature is reduced to-164 DEG C, pressure drop as little as 1.38MPa, then through being installed on N2—CH4Exporting the choke valve throttling in U-shaped adapter 12, pressure drop as little as 0.3MPa after throttling, after throttling, nitrogen temperature becomes-185 DEG C, being in gas-liquid two-phase state, after throttling, methane temperature becomes-163.5 DEG C, is in undercooling state, after throttling, mix refrigerant is gas-liquid two-phase, then through N2—CH4Export U-shaped adapter 12 and enter N after throttling2—CH4Import bobbin carriage 19, N after throttling2—CH4Import arranges N after the throttling in each import entrance often group interlayer2—CH4Side interlayer, flows up cooling N2—CH4After side interlayer, natural gas side interlayer ,-130 DEG C, 0.3MPa time, through throttling after N2—CH4Outlet arranges each outlet, enters N after throttling2—CH4Outlet bobbin carriage 6 converges, then N after throttling2—CH4Discharge connection 5 flows out three tier structure cold drawing fin heat exchanger and enters two-stage system cold drawing fin heat exchanger.
Natural gas-120 DEG C, 5.5MPa time enter Imported gas bobbin carriage 3, be allocated in Imported gas bobbin carriage 3 Imported gas arrange each import, by each import enter back into often group interlayer in natural gas side interlayer, be throttled rear N2—CH4Mix refrigerant pre-cooling in the interlayer of side, after pre-cooling temperature be reduced to-164 DEG C, pressure drop as little as 5.3MPa time liquefaction, it flow to gas outlet bobbin carriage 16 through gas outlet row after liquefaction, then flow out three tier structure device for cooling through gas outlet adapter 15, after reducing pressure by regulating flow, send into LNG basin.
During choke valve work, N2—CH4Circular passage between choke valve valve seat 35 and choke valve valve body 44 is entered from choke valve valve seat 35 top, right side through hole, and act on throttle valve stem 43 conical seal (contact) face, when pressure sets preload pressure more than throttle valve spring 36, promote throttle valve stem 43, driving choke valve valve gap 39 to left movement, choke valve is opened and throttling refrigerant.Choke valve sets pressure and can set according to system design temperature, being regulated by throttle valve spring 36 pretightning force between choke valve valve gap 39 and throttle valve stem 43, pretightning force is by rotary barrel throttle valve gap 39 and changes the method for throttle valve spring 36 pretension height and realizes throttling refrigeration；Choke valve must carry out throttling test between installing and accurately regulate, and the satisfied throttling of regulation is installed on N after requiring2—CH4Export U-shaped adapter 12 and manage interior.
Claims (3)
- Cold three stream plate-fin heat exchanger of 1.LNG low-temperature liquefaction three tier structure, including N after Imported gas flange 1, Imported gas adapter 2, Imported gas bobbin carriage 3, throttling2—CH4N after outlet(discharge) flange 4, throttling2—CH4N after discharge connection 5, throttling2—CH4N after outlet bobbin carriage 6, throttling2—CH4Outlet deflector 7, flap 8, left strip of paper used for sealing 9, lower strip of paper used for sealing 10, N2—CH4Outlet bobbin carriage 11, N2—CH4Export N after U-shaped adapter 12, choke valve 13, gas outlet flange 14, gas outlet adapter 15, gas outlet bobbin carriage 16, throttling2—CH4N after suction flange 17, throttling2—CH4N after entrance sleeve 18, throttling2—CH4N after import bobbin carriage 19, throttling2—CH4Import deflector 20, right strip of paper used for sealing 21, upper strip of paper used for sealing 22, N2—CH4Suction flange 23, N2—CH4Entrance sleeve 24, N2—CH4Import bobbin carriage 25, Imported gas deflector 26, gas outlet deflector 27, N2—CH4Import deflector 28, N2—CH4Outlet deflector 29, dividing plate 30, front panel 31, rear board 32；Described choke valve 13, including the conical surface the first sealing ring 33, the conical surface the second sealing ring 34, choke valve valve seat 35, throttle valve spring 36, clip 37, pin rod 38, choke valve valve gap 39, housing screw 40, spring the first packing ring 41, spring the second packing ring 42, throttle valve stem 43, choke valve valve body 44；It is characterized in that: the most alternate between front panel 31 with rear board 32 be connected flap 8 and dividing plate 30；Flap 8 top is sequentially connected with N after throttling2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4Import deflector 28, and formed organize connection more；Flap 8 bottom is sequentially connected with N after throttling2—CH4Import deflector 20, gas outlet deflector 27, N2—CH4Export deflector 29, and connection is organized in formation more；Left strip of paper used for sealing 9 is sequentially connected on the left of heat exchanger between dividing plate 30；Right strip of paper used for sealing 21 is sequentially connected between heat exchanger right side partition 30；Upper strip of paper used for sealing 21 is sequentially connected on the upside of heat exchanger between dividing plate 30, and has each fluid streams access way successively；Lower strip of paper used for sealing 10 is sequentially connected on the downside of heat exchanger between dividing plate 30, and has each fluid streams access way successively；N after throttling2—CH4N after exit passageway and throttling2—CH4Intake channel is positioned at same layer, and forms N after throttling2—CH4Side interlayer；Imported gas passage and gas exit passageway are positioned at same layer, and form natural gas side interlayer；N2—CH4Intake channel and N2—CH4Exit passageway is positioned at same layer, and forms N2—CH4Side interlayer；N after throttling2—CH4Side interlayer, natural gas side interlayer, N2—CH4Side interlayer is arranged in order one group of interlayer of formation, and many group interlayers are arranged in order composition overall heat exchange device；Often N after the throttling in group interlayer2—CH4Outlet, Imported gas, N2—CH4Three row are lined up in import successively at heat exchanger top, and sequentially form N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Import arranges；N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Import row top connects N after the throttling of semicircle column type the most respectively2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH4Import bobbin carriage 25；N after throttling2—CH4Outlet row, Imported gas row, N2—CH4Bottom import row, each mouth connects N after throttling the most respectively2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4Import deflector 28；N after throttling2—CH4Outlet deflector 7, Imported gas deflector 26, N2—CH4Flap 8 top in each interlayer is connected the most respectively bottom import deflector 28；N after throttling2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH425 3 bobbin carriages of import bobbin carriage are arranged in order and are connected to heat exchanger top；N after throttling2—CH4Outlet bobbin carriage 6, Imported gas bobbin carriage 3, N2—CH4Import bobbin carriage 25 top connects N after throttling respectively2—CH4Discharge connection 5, Imported gas adapter 2, N2—CH4Entrance sleeve 24；N after throttling2—CH4Discharge connection 5, Imported gas adapter 2, N2—CH4Entrance sleeve 24 top connects N after throttling respectively2—CH4Outlet(discharge) flange 4, Imported gas flange 1, N2—CH4Suction flange 23；The often N in group interlayer2—CH4N after outlet, gas outlet, throttling2—CH4Import lines up three row successively at exchanger base, and sequentially forms N2—CH4N after outlet row, gas outlet row, throttling2—CH4Import arranges；N2—CH4N after outlet row, gas outlet row, throttling2—CH4Semicircle column type N is connected the most respectively bottom import row2—CH4N after outlet bobbin carriage 11, gas outlet bobbin carriage 16, throttling2—CH4Import bobbin carriage 19；N2—CH4N after outlet row, gas outlet row, throttling2—CH4Import row top connects N the most respectively2—CH4N after outlet deflector 29, gas outlet deflector 27, throttling2—CH4Import deflector 20；N2—CH4N after outlet deflector 29, gas outlet deflector 27, throttling2—CH4Import deflector 20 top connects in each interlayer bottom flap 8 the most respectively；N2—CH4N after outlet bobbin carriage 11, gas outlet bobbin carriage 16, throttling2—CH419 3 bobbin carriages of import bobbin carriage are arranged in order and are connected to exchanger base；N after gas outlet bobbin carriage 16, throttling2—CH4Gas outlet is connected respectively by N after pipe 15, throttling bottom import bobbin carriage 192—CH4Entrance sleeve 18；Gas outlet presses N after pipe 15, throttling2—CH4N after gas outlet flange 14, throttling is connected respectively bottom entrance sleeve 182—CH4Suction flange 17；N2—CH4N is connected bottom outlet bobbin carriage 112—CH4Export U-shaped adapter 12；N2—CH4Export and on the right side of U-shaped adapter 12, connect N after throttling2—CH4Import bobbin carriage 19, choke valve 13 is installed at middle part；Threaded choke valve valve gap 39 on the right side of throttle valve stem 43；Choke valve valve gap 39 is installed in choke valve valve seat 35；Choke valve valve seat 35 connects throttling valve body 44 by housing screw 40；Pin rod 48 is through choke valve valve gap 39 and throttle valve stem 43；Clip 37 is installed in choke valve valve gap 39 draw-in groove；Throttle valve spring 36 is installed in choke valve valve gap 39 and choke valve valve seat 35, and center is throttle valve stem 43, and right side contacts with spring the first packing ring 41, and left side contacts with spring the second packing ring 42；On the left of throttle valve spring 36 pretension throttle valve stem 43, on the left of the spool conical surface and choke valve valve body 44, diffusion cover inner surface forms sealing surface；The conical surface the first sealing ring 33, the conical surface the second sealing ring 34 are installed on the left of throttle valve stem 43 in spool conical surface seal groove the most successively.
- 2. according to claim1The heat-exchanging process method of described cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure, it is characterised in that: N2—CH4N is entered when-120 DEG C and 1.58MPa2—CH4Import bobbin carriage 25, at N2—CH4It is allocated in N in import bobbin carriage 252—CH4Import arranges each import, is entered back into by each import and often organizes the N in interlayer2—CH4Side interlayer, the N after being throttled2—CH4Mix refrigerant pre-cooling is liquefied, then through N2—CH4Outlet arranges each outlet and flow to N2—CH4Outlet bobbin carriage 11, temperature is reduced to-164 DEG C, pressure drop as little as 1.38MPa, then through being installed on N2—CH4Exporting the choke valve throttling in U-shaped adapter 12, pressure drop as little as 0.3MPa after throttling, after throttling, nitrogen temperature becomes-185 DEG C, being in gas-liquid two-phase state, after throttling, methane temperature becomes-163.5 DEG C, is in undercooling state, after throttling, mix refrigerant is gas-liquid two-phase, then through N2—CH4Export U-shaped adapter 12 and enter N after throttling2—CH4Import bobbin carriage 19, N after throttling2—CH4Import arranges N after the throttling in each import entrance often group interlayer2—CH4Side interlayer, flows up cooling N2—CH4After side interlayer, natural gas side interlayer ,-130 DEG C, 0.3MPa time, through throttling after N2—CH4Outlet arranges each outlet, enters N after throttling2—CH4Outlet bobbin carriage 6 converges, then N after throttling2—CH4Discharge connection 5 flows out three tier structure cold drawing fin heat exchanger and enters two-stage system cold drawing fin heat exchanger.
- 3. according to claim1The heat-exchanging process method of described cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure, it is characterized in that: natural gas-120 DEG C, 5.5MPa time enter Imported gas bobbin carriage 3, in Imported gas bobbin carriage 3, it is allocated in Imported gas arranges each import, entered back into by each import and often organize the natural gas side interlayer in interlayer, be throttled rear N2—CH4Mix refrigerant pre-cooling in the interlayer of side, after pre-cooling temperature be reduced to-164 DEG C, pressure drop as little as 5.3MPa time liquefaction, it flow to gas outlet bobbin carriage 16 through gas outlet row after liquefaction, then flow out three tier structure device for cooling through gas outlet adapter 15, after reducing pressure by regulating flow, send into LNG basin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510231972.6A CN106123484A (en) | 2015-05-09 | 2015-05-09 | Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510231972.6A CN106123484A (en) | 2015-05-09 | 2015-05-09 | Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106123484A true CN106123484A (en) | 2016-11-16 |
Family
ID=57471485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510231972.6A Pending CN106123484A (en) | 2015-05-09 | 2015-05-09 | Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106123484A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110925097A (en) * | 2019-10-30 | 2020-03-27 | 北京动力机械研究所 | Low-flow-resistance efficient compact precooler and manufacturing method thereof |
| CN116116025A (en) * | 2023-01-31 | 2023-05-16 | 安徽东科新材料有限公司 | Device and process for preparing diethyl carbonate based on dimethyl carbonate exchange method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10259991A (en) * | 1997-01-17 | 1998-09-29 | Kobe Steel Ltd | Heat exchanger for air separation device and air separation device |
| CN1813166A (en) * | 2003-05-30 | 2006-08-02 | 环球油品公司 | Method for making brazed heat exchanger and apparatus |
| CN101194137A (en) * | 2005-06-09 | 2008-06-04 | 乔治洛德方法研究和开发液化空气有限公司 | Plate heat exchanger with exchanging structure forming several channels in a passage |
| CN101614465A (en) * | 2009-07-16 | 2009-12-30 | 杭州杭氧股份有限公司 | A kind of plate-fin thermal coupling rectification device |
| CN102563157A (en) * | 2011-10-08 | 2012-07-11 | 张周卫 | Midstream low-temperature process control pressure reduction throttling valve |
| CN103063057A (en) * | 2013-01-30 | 2013-04-24 | 张周卫 | Three-flow low-temperature coiling tubular heat exchanger for feed gas cooler |
| CN103438667A (en) * | 2013-08-16 | 2013-12-11 | 张周卫 | Three-stage back heating multi-strand winding pipe type heat exchange device for low-temperature liquid nitrogen |
-
2015
- 2015-05-09 CN CN201510231972.6A patent/CN106123484A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10259991A (en) * | 1997-01-17 | 1998-09-29 | Kobe Steel Ltd | Heat exchanger for air separation device and air separation device |
| CN1813166A (en) * | 2003-05-30 | 2006-08-02 | 环球油品公司 | Method for making brazed heat exchanger and apparatus |
| CN101194137A (en) * | 2005-06-09 | 2008-06-04 | 乔治洛德方法研究和开发液化空气有限公司 | Plate heat exchanger with exchanging structure forming several channels in a passage |
| CN101614465A (en) * | 2009-07-16 | 2009-12-30 | 杭州杭氧股份有限公司 | A kind of plate-fin thermal coupling rectification device |
| CN102563157A (en) * | 2011-10-08 | 2012-07-11 | 张周卫 | Midstream low-temperature process control pressure reduction throttling valve |
| CN103063057A (en) * | 2013-01-30 | 2013-04-24 | 张周卫 | Three-flow low-temperature coiling tubular heat exchanger for feed gas cooler |
| CN103438667A (en) * | 2013-08-16 | 2013-12-11 | 张周卫 | Three-stage back heating multi-strand winding pipe type heat exchange device for low-temperature liquid nitrogen |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110925097A (en) * | 2019-10-30 | 2020-03-27 | 北京动力机械研究所 | Low-flow-resistance efficient compact precooler and manufacturing method thereof |
| CN116116025A (en) * | 2023-01-31 | 2023-05-16 | 安徽东科新材料有限公司 | Device and process for preparing diethyl carbonate based on dimethyl carbonate exchange method |
| CN116116025B (en) * | 2023-01-31 | 2023-09-01 | 安徽东科新材料有限公司 | Device and process for preparing diethyl carbonate based on dimethyl carbonate exchange method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102538387A (en) | Liquefied natural gas (LNG) low temperature liquefied three-level refrigeration spiral wound tube type heat exchanger | |
| CN102636000B (en) | Method for refrigerating liquefied natural gas by aid of single mixed working medium and device | |
| CN202328997U (en) | Device for refrigerating liquefied natural gas by adopting single mixed working medium | |
| CN101967413A (en) | Method and device for liquefying natural gas via refrigeration of single mixed refrigerant | |
| CN102538388B (en) | Three-stream spiral wound type heat exchange equipment for secondary refrigeration and low-temperature liquefaction of LNG (liquefied natural gas) | |
| CN104513680B (en) | Technology and device for removing hydrogen and nitrogen from methane-rich gas through rectification and producing liquefied natural gas | |
| CN202361751U (en) | Device for refrigerating liquefied natural gas by adopting single mixed refrigerant | |
| CN102748919A (en) | Single-cycle mixed-refrigerant four-stage throttling refrigeration system and method | |
| CN102564056B (en) | Multi-flow spiral winding tube type main heat exchange equipment with mixed refrigerant for low-temperature liquefaction of LNG (liquefied natural gas) | |
| CN204678750U (en) | A kind of natural gas liquefaction device realizing mix refrigerant recovery, re-injection | |
| CN102492505A (en) | Two-section type single loop mixed refrigerant natural gas liquefaction process and device | |
| CN105890281A (en) | Skid-mounted natural gas liquefaction and purification integrated cold box | |
| CN201672830U (en) | Temperature grade integrated heat exchanger | |
| CN102538391A (en) | Multi-level single-component refrigeration natural gas liquefaction system and multi-level single-component refrigeration natural gas liquefaction method | |
| CN201762300U (en) | Device using single-mixed refrigerant refrigeration to liquefy natural gas | |
| CN104807287A (en) | Small natural gas liquefaction and refrigeration system and small natural gas liquefaction and refrigeration method | |
| CN106123484A (en) | Cold three stream plate-fin heat exchanger of LNG low-temperature liquefaction three tier structure | |
| CN202432825U (en) | Device adopting single refrigeration of mixed working mediums to liquefy natural gas | |
| CN102628634A (en) | Ternary-cycle cascade refrigeration natural gas liquefaction system and method thereof | |
| CN202494271U (en) | Device for liquefying natural gas through refrigeration of single mixed working medium | |
| CN110398132B (en) | Helium liquefying and different temperature grade helium cold source supply device | |
| CN102455113B (en) | Liquefied natural gas (LNG) low-temperature liquefied primary refrigerating four-stream spiral twined pipe type heat exchange equipment | |
| CN109458788B (en) | BOG self-circulation re-liquefaction recovery heat exchange system and method for LNG storage tank | |
| CN103438667B (en) | Low temperature liquid nitrogen three grades of backheat multiple flows are wound around pipe type heat transfer equipment | |
| CN202853257U (en) | Natural gas mixed refrigerant liquefying device adopting promoting technology of liquid phase refrigerant |
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: 20161116 |