CN202339064U - Double-refrigerant liquefaction system for natural gas - Google Patents
Double-refrigerant liquefaction system for natural gas Download PDFInfo
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- CN202339064U CN202339064U CN 201120409354 CN201120409354U CN202339064U CN 202339064 U CN202339064 U CN 202339064U CN 201120409354 CN201120409354 CN 201120409354 CN 201120409354 U CN201120409354 U CN 201120409354U CN 202339064 U CN202339064 U CN 202339064U
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 206
- 239000003345 natural gas Substances 0.000 title claims abstract description 102
- 239000003507 refrigerant Substances 0.000 title claims abstract description 54
- 238000001816 cooling Methods 0.000 claims abstract description 136
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 87
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 87
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract description 86
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000007788 liquid Substances 0.000 claims abstract description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 24
- 239000012530 fluid Substances 0.000 claims description 15
- 229910052757 nitrogen Inorganic materials 0.000 claims description 12
- 239000012071 phase Substances 0.000 claims description 8
- 239000007791 liquid phase Substances 0.000 claims description 7
- 239000003463 adsorbent Substances 0.000 claims description 6
- 239000000428 dust Substances 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 6
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 6
- 229910052753 mercury Inorganic materials 0.000 claims description 6
- 239000011810 insulating material Substances 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 4
- 235000019628 coolness Nutrition 0.000 claims description 3
- 239000000446 fuel Substances 0.000 claims description 3
- 238000005265 energy consumption Methods 0.000 abstract description 6
- 238000000926 separation method Methods 0.000 abstract 3
- 210000000038 chest Anatomy 0.000 description 21
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 10
- 239000002826 coolant Substances 0.000 description 10
- 238000000034 method Methods 0.000 description 8
- 239000001294 propane Substances 0.000 description 5
- 238000005057 refrigeration Methods 0.000 description 5
- 239000003570 air Substances 0.000 description 4
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 239000000110 cooling liquid Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000005219 brazing Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000012080 ambient air Substances 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001932 seasonal effect Effects 0.000 description 1
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Abstract
The utility model relates to a two cryogen liquefaction systems of natural gas. The system comprises a first refrigerant external treatment subsystem, a first refrigerant cooling subsystem, a second refrigerant external treatment subsystem, a second refrigerant cooling subsystem, a heavy hydrocarbon separation tank and a denitrification tank; the first refrigerant cooling subsystem comprises an NG precooling channel, a first refrigerant cooling channel and a second refrigerant first-section precooling channel; the second refrigerant cooling subsystem comprises: the system comprises an NG deep cooling channel, a second refrigerant two-section precooling channel and a second refrigerant cooling channel; the first refrigerant external processing subsystem comprises a first refrigerant buffer tank, a first refrigerant compressor, a first refrigerant air cooler, a first refrigerant water cooler and a first refrigerant gas-liquid separation tank; the second refrigerant external processing subsystem comprises a second refrigerant buffer tank, a second refrigerant compressor, a second refrigerant air cooler, a second refrigerant water cooler and a second refrigerant gas-liquid separation tank; the system can reduce the complexity and energy consumption of the system.
Description
Technical field
The utility model relates to the natural gas liquefaction technical field, particularly relates to a kind of two refrigerants liquefaction system of natural gas.
Background technology
The ice chest that the existing azeotrope refrigeration process of natural gas (NG) is adopted is for around tubular type or still formula, and its structure is as depicted in figs. 1 and 2 respectively.In the tubular type ice chest; Shell 101 internal fixation one are around tube core tube 102; Carrying the cryogen transfer passage 103 of normal temperature cryogen and NG to intersect thick and fast with NG transfer passage 104 respectively is wrapped on tube core tube 102; Space between shell 101 and cryogen transfer passage 103, the NG transfer passage 104 is a shell-side, and the cryogen of low temperature flows at this shell-side from top to bottom, like this; Normal temperature cryogen of carrying respectively in cryogen transfer passage 103 and the NG transfer passage 104 and NG just carry out exchange heat with the outer cryogenic coolant of passage respectively; The cryogenic coolant of shell-side discharges cold and is evaporated to the normal temperature cryogen, and the NG in normal temperature cryogen and the NG transfer passage 104 is cooled in the cryogen transfer passage 103, has so just realized to the cooling liquid of NG with to the precooling of normal temperature cryogen.In still formula ice chest, cryogenic coolant is input to the inner shell-side of shell 105 from the cryogenic coolant input pipe 106 of shell 105 bottoms, behind released cold quantity, becomes cryogenic coolant efferent duct 107 outputs of steam from shell 105 tops.Normal temperature cryogen and NG get into shell 105 inside along cryogen transfer passage 110 and NG transfer passage 111 respectively; And become coil form in shell 105 inside to improve the contact area with cryogenic coolant, like this, just inner and cryogenic coolant carries out cold and exchanges with shell 105 for normal temperature cryogen and NG; Cryogenic coolant is heated and gasifies; And the normal temperature cryogen is by precooling, and NG is cooled, and outputs to shell 105 outsides through normal temperature cryogen efferent duct 109 and NG efferent duct 112 respectively.Through regulating the input flow rate of cryogenic coolant, normal temperature cryogen and NG; Can make liquid cryogenic coolant remain on the position (promptly being higher than the position that the normal temperature cryogen is carried coil pipe and NG carries coil pipe) of dotted line 108 among Fig. 2, carry out smoothly with what guarantee that cold exchanges at shell-side.
The passage (being shell-side) of a cold fluid can only be set in two kinds of ice chests illustrated in figures 1 and 2; Hot fluid (like normal temperature cryogen, NG etc.) can be through carrying around the mode of pipe (like cryogen transfer passage 103, NG transfer passage 104 etc.) on tube core tube 102, twining a plurality of hot fluids, thereby prior art can arrange multiple hot fluid and same cold fluid to carry out exchange heat.But, when needing two or more cold fluid (like a cryogen and No. two cryogens in the azeotrope refrigeration process) and simultaneously carry out heat exchange, then need the ice chest of two Fig. 1 or structure shown in Figure 2 could accomplish this technology at least with hot fluid.The structure chart of the liquefaction system that Fig. 3 is adopted for existing azeotrope refrigeration process.As shown in Figure 3, heat exchanger 201 and No. two heat exchangers 202 can for structure shown in Figure 1 around the tubular type ice chest, also can be still formula ice chest shown in Figure 2.No. one heat exchanger 201 utilizes a cryogen to realize the precooling to NG; Cryogen here can be propane; Also can be azeotrope (like the mixture of ethane, propane, pentane etc.); The mixture that No. two heat exchangers 202 utilize nitrogen and lighter hydrocarbons (like methane, ethane, propane, butane etc.) is realized deep cooling and liquefaction to NG as No. two cryogens, finally obtains LNG output.Its technological process is: after heat exchanger 201 utilizes the cold of the cold cryogen that cryogen cooling system 204 sends here that NG is carried out precooling; A cryogen of heat is delivered to a cryogen cooling system 204 to cool; The heavy hydrocarbon component that absorbs the liquid state that obtains behind the cold is separated; The light hydrocarbon component of gaseous state is transported to No. two heat exchangers 202 through light hydrocarbon component carrier pipe 203 carries out deep cooling; The cold that No. two heat exchangers 202 utilize No. two cold cryogens that No. two cryogen cooling systems 205 send here carries out deep cooling and liquefaction to the light hydrocarbon component of this gaseous state; Thereby obtain LNG output, and No. two cryogens of heat are delivered to No. two cryogen cooling systems 205 cool.
It is thus clear that; Existing azeotrope liquefaction system shown in Figure 3 liquefies to NG, will have two ice chests just can meet the demands at least, and two kinds of cryogens in this technology work alone; And independently cool off, thereby the complexity of whole liquefaction system and energy consumption are all than higher.In addition, when a cryogen adopted propane, its physical characteristic had determined that its minimum temperature that can reach the precooling of NG is about-40 ℃ a fixed value; Thereby when the composition of NG changes; Perhaps in environment temperature during with seasonal variations, the LNG output of this liquefaction system will be unstable, when especially reaching below-40 ℃ at ambient air temperature; The liquefaction of NG has not needed the precooling of propane; If but do not launch 201 work of heat exchanger, whole liquefaction system can't be worked, thus the energy consumption of this liquefaction system quite greatly.
The utility model content
The utility model purpose provides a kind of two refrigerants liquefaction system of natural gas, can reduce the complexity and the energy consumption of system.
The two refrigerants liquefaction system of the described a kind of natural gas of the utility model, this system comprises:
Extracting tower 57, drier 58, mercury deviate from jars 59, dust filter unit 60, BOG cooler 62, compressor 61, heat exchanger 54, cryogen external treatment subsystem, cryogen cooling subsystem 01, No. two cryogen external treatment subsystems, No. two cryogens coolings subsystem 02, heavy hydrocarbon knockout drum 23 and denitrogenation jars 41;
Wherein, cryogen cooling subsystem 01 comprises: NG precooling passage 11, cryogen precooling passage 12, cryogen cooling duct 13 and one section precooling passage 14 of No. two cryogens;
No. two cryogens cooling subsystem 02 comprises: NG deep cooling passage 15, No. two two sections precooling passages 16 of cryogen and No. two cryogen cooling ducts 17;
No. one cryogen external treatment subsystem comprises: cryogen surge tank 63, cryogen compressor 64, cryogen aerial cooler 65, a water as refrigerant cooler 66 and a cryogen knockout drum 20;
No. two cryogen external treatment subsystem comprises: No. two cryogen surge tanks 67, No. two cryogen compressors 68, No. two cryogen aerial coolers 69, No. two water as refrigerant coolers 70 and No. two cryogen knockout drums 36;
Extracting tower 57, drier 58, mercury are deviate from jar 59, dust filter unit 60 connects the back successively and is connected with heat exchanger 54NG pipe input through NG carrier pipe 55; Heat exchanger 54NG pipe output is connected through NG precooling passage 11 inputs of NG carrier pipe 56 with a cryogen cooling subsystem 01; NG precooling passage 11 outputs are connected with heavy hydrocarbon knockout drum 23 through NG carrier pipe 24; Heavy hydrocarbon knockout drum 23 bottoms carry control valve 29 to be connected with heavy hydrocarbon storage tank 30 through heavy hydrocarbon carrier pipe 28, heavy hydrocarbon; Heavy hydrocarbon storage tank 30 passes through heavy hydrocarbon delivery pump 31, heavy hydrocarbon carrier pipe 33 and defeated stop valve 32 outward and is connected with outer defeated heavy hydrocarbon system; Heavy hydrocarbon knockout drum 23 and heavy hydrocarbon are carried between the control valve 29 and are connected with No. two liquid level detectors 26 and No. three controllers; Be connected with No. three liquid level detectors 26 and No. four controllers between heavy hydrocarbon storage tank 30 and the outer defeated stop valve 32; The cryogen surge tank 63 of a cryogen external treatment subsystem, cryogen compressor 64, a cryogen aerial cooler 65 are connected with a water as refrigerant cooler 66 successively; Be connected with the output of a cryogen cooling duct 13 of a cryogen cooling subsystem 01 through a cryogen surge tank 63, be connected with cryogen precooling passage 12 inputs of a cryogen cooling subsystem 01 through a water as refrigerant cooler; No. one cryogen precooling passage 12 outputs are connected with cryogen knockout drum 20 inputs with shutoff valve 19 through pipeline 18, and No. one cryogen knockout drum 20 outputs are connected with the input of liquid phase pipeline 22 with a cryogen cooling duct 13 through gas phase pipeline 21;
NG deep cooling passage 15 inputs of No. two cryogen cooling subsystems 02 are connected with heavy hydrocarbon knockout drum 23 tops through pipeline 25; NG deep cooling passage 15 outputs are connected with denitrogenation jar 41 with pressure-reducing valve 43 through pipeline 42, are connected with controller 44 and pressure gauge 45 between pressure-reducing valve 43 and the denitrogenation jar 41; No. two cryogen precooling passage 16 inputs are connected with one section precooling passage 14 of No. two cryogens of a cryogen cooling subsystem 01; No. two cryogen precooling passage 16 outputs are connected with No. two cryogen knockout drums 36 with valve 38 through pipeline 37, and No. two cryogen knockout drum 36 is connected with No. two cryogen cooling duct 17 inputs with gas phase pipeline 40 through liquid phase pipeline 39; No. two cryogen cooling duct 17 outputs are connected with No. two cryogen surge tank 67 inputs of No. two cryogen external treatment subsystems; After No. two cryogen surge tanks 67 of No. two cryogen external treatment subsystems, No. two cryogen compressors 68, No. two cryogen aerial coolers 69, No. two water as refrigerant coolers 70 connected successively, the output through No. two water as refrigerant coolers 70 was connected with one section precooling passage 14 of No. two cryogens of a cryogen cooling subsystem 01;
Denitrogenation jar 41 bottoms are connected with LNG storage tank 46 through LNG delivery pump 47, LNG control valve 49, pipeline 48; Be connected with a liquid level detector 50 and No. two controllers 51 between LNG storage tank 46 and the LNG control valve 49; LNG storage tank 46 is connected with cold input pipe 523 through tube connector 53; Denitrogenation jar 41 tops are connected with cold input pipe 523 through pipeline 52; Cold input pipe 523 is connected with heat exchanger 54; Heat exchanger 54 is connected with BOG cooler 62 through compressor 61, and BOG cooler 62 connects fuel system.
NG precooling passage, a cryogen precooling passage, one section precooling passage of No. two cryogens, a cryogen cooling duct of described cryogen cooling subsystem place a shell; NG deep cooling passage, two sections precooling passages of No. two cryogens, No. two cryogen cooling ducts of described No. two cryogens cooling subsystem place another shell; Be filled with heat-insulating material with passage space each other in the shell.
Said shell is provided with breather valve; The adsorbent that is used to absorb water is filled in the inside of said breather valve.
The space that said enclosure is filled said heat-insulating material also is filled with the nitrogen of air pressure greater than external atmosphere pressure; Then the top of said shell is provided with more than one superpressure safety valve.
Described NG precooling passage, NG deep cooling passage, a cryogen precooling passage, a cryogen cooling duct, one section precooling passage of No. two cryogens, two sections precooling passages of No. two cryogens, No. two cryogen cooling ducts are the transfer passage of the fluid of the both ends open that fin, flow deflector, dividing plate and strip of paper used for sealing form; Its structure is: in the middle of two dividing plates, place one deck fin; Flow deflector is placed in the front and back of fin; Strip of paper used for sealing is placed in the left and right sides of fin and flow deflector, constitutes the fluid supplying passage of a both ends open.
In the above-mentioned system architecture; The NG that NG input pipe 56 is input in the NG precooling passage 11 is the gaseous material of low normal pressure and temperature (20 ℃ to 50 ℃); It comprises the heavy hydrocarbon component of gaseous state and the light hydrocarbon component of gaseous state; After the cold that this NG is provided by the cryogen of low-pressure low-temperature in cryogen cooling duct 13 in NG precooling passage 11 is cooled to-20 ℃ to-70 ℃; Heavy hydrocarbon component wherein is liquefied and is separated for liquid state is transported in the heavy hydrocarbon knockout drum 23; And light hydrocarbon component still is a gaseous material, after this light hydrocarbon component gets into NG deep cooling passages 15 from the gas-phase space of heavy hydrocarbon knockout drum 23 through pipeline 25, absorbs the cold that No. two No. two cryogens of low-pressure low-temperature in the cryogen cooling duct 17 are provided again and is further cooled and liquefies and be the LNG below-160 ℃; Be transported in the denitrogenation jar 41 through pipeline 42, thereby finally realized the liquefaction of all NG.In this liquefaction process; The temperature that cryogen precooling passage 12 is transported to a cryogen of high pressure low temperature of a cryogen cooling subsystem is about-20 ℃ to-70 ℃ or higher slightly, and cryogen cooling subsystem is transported to the temperature of a cryogen of low-pressure low-temperature of a cryogen cooling duct 13 than cryogen of high pressure low temperature low (hanging down 3 ℃ to 5 ℃ approximately); The temperature that two sections precooling passages 16 of No. two cryogens are transported to No. two cryogens of high pressure low temperature of No. two cryogens cooling subsystems is about-160 ℃ or higher slightly, and No. two cryogen cooling subsystems are transported to the temperature of No. two cryogens of low-pressure low-temperature of No. two cryogen cooling ducts 17 than No. two cryogens of high pressure low temperature low (hanging down 3 ℃ to 5 ℃ approximately).
Cryogen precooling passage 12 is used to carry and cools off cryogen of high normal pressure and temperature that cryogen external treatment subsystem is sent here; And cryogen of the high pressure low temperature that obtains is delivered to a cryogen cooling subsystem further lower the temperature; Here, cryogen precooling passage 12 is cryogen of a low-pressure low-temperature in the cryogen cooling duct 13 to the cold source that cryogen of high normal pressure and temperature of its conveying cools off.
One section precooling passage 14 of No. two cryogens is used to carry and cools off No. two cryogens of high normal pressure and temperature that No. two cryogen external treatment subsystems are sent here; And with in the high pressure that obtains the temperature No. two cryogens deliver to two sections precooling passages 16 of No. two cryogens; Here, No. two cryogens of high normal pressure and temperature of 14 pairs of conveyings of one section precooling passage of No. two cryogens cold source of cooling off is cryogen of a low-pressure low-temperature in the cryogen cooling duct 13.
Carry cryogen cooling duct 13 is cryogen of low-pressure low-temperature that cryogen cooling subsystem is sent here; Because the temperature of a cryogen of this low-pressure low-temperature is all lower than the cryogen of high normal pressure and temperature in the NG in the NG precooling passage 11, the cryogen precooling passage 12, the temperature of No. two cryogens of high normal pressure and temperature in one section precooling passage 14 of No. two cryogens, thereby can cool off the cryogen of high normal pressure and temperature in the NG in the NG precooling passage 11, the cryogen precooling passage 12, No. two cryogens of high normal pressure and temperature in one section precooling passage 14 of No. two cryogens.A cryogen cooling duct 13 also loses the cryogen of low normal pressure and temperature that obtains behind the cold with cryogen of low-pressure low-temperature and delivers to cryogen external treatment subsystem No. one; These cryogen being compressed again and liquefy, thereby make it get into next cool cycles.
Two sections precooling passages 16 of No. two cryogens are used for carrying and cooling off No. two cryogens of high pressure temperature that one section precooling passage 14 of No. two cryogens is sent here; And No. two cryogens of the high pressure low temperature that obtains are delivered to No. two cryogens cooling subsystem; Here, the cold source that No. two cryogens of temperature cool off in the high pressure of 16 pairs of conveyings of two sections precooling passages of No. two cryogens is No. two cryogens of low-pressure low-temperature of carrying in No. two cryogen cooling ducts 17.
No. two cryogens of low-pressure low-temperature that No. two cryogen cooling ducts 17 are used to carry No. two cryogen cooling subsystems to send here; The temperature of No. two cryogens of this low-pressure low-temperature is all lower than the temperature of No. two cryogens of temperature in the high pressure in the light hydrocarbon component of gaseous state in the NG deep cooling passage 15, two sections precooling passages 16 of No. two cryogens, thereby can cool off No. two cryogens of temperature in the high pressure in the light hydrocarbon component of gaseous state in the NG deep cooling passage 15, two sections precooling passages 16 of No. two cryogens.No. two cryogen cooling ducts 17 also lose No. two cryogens of low normal pressure and temperature that obtain behind the cold with No. two cryogens of low-pressure low-temperature and deliver to cryogen external treatment subsystem No. two, again these No. two cryogens being compressed and cool off, thereby get into next cool cycles.
In the utility model; To be divided into two sections to the liquefaction process of NG; Utilize the liquefaction of NG precooling passage 11 realizations, and export it to heavy hydrocarbon knockout drum 23, and the light hydrocarbon component of gaseous state cools off from the gas-phase space entering NG deep cooling passage 15 of heavy hydrocarbon knockout drum 23 and liquefies the heavy hydrocarbon component; This heavy hydrocarbon component that can prevent liquid state is freezed in the temperature-fall period of NG deep cooling passage 15, causes the obstruction of equipment, pipeline and valve.
In the utility model, heavy hydrocarbon knockout drum 23 can adopt the form of tank body, also can adopt the form of heavy hydrocarbon knockout tower.Heavy hydrocarbon constituent content in raw material NG is too high; When the heavy hydrocarbon knockout drum 23 of tank body form can not be realized separating fully of heavy hydrocarbon component and light hydrocarbon component; Can heavy hydrocarbon knockout drum 23 be designed to the form of heavy hydrocarbon knockout tower; With respect to the heavy hydrocarbon knockout drum of tank body form, the heavy hydrocarbon knockout tower is more complete to the separating effect of heavy hydrocarbon component and light hydrocarbon component, and this can satisfy the heavy hydrocarbon components contents requirement of ice chest to being mixed in the light hydrocarbon component; The heavy hydrocarbon component that prevents to remain in the light hydrocarbon component is freezed in the temperature-fall period of NG deep cooling passage 15, causes the obstruction of equipment, pipeline and valve.
Ice chest in the utility model can adopt the vacuum brazing aluminum plate-fin heat exchanger to realize; Its inside can be carried out the heat exchange between multiply cold fluid and the multiply hot fluid simultaneously; Satisfied the requirement that the azeotrope refrigeration process cools off and liquefies at different potential temperatures respectively NG; And cryogen and No. two cryogens that NG carries out precooling and deep cooling have respectively all only been carried out the liquefaction that once cooling has promptly realized heavy hydrocarbon component and light hydrocarbon component respectively; Thereby the liquefaction efficiency of the utility model is than higher, and the volume of ice chest is little, and wear life is long.
Inflated with nitrogen in the space of portion's filling heat insulator in the enclosure; And the nitrogen pressure that makes enclosure is greater than external atmosphere pressure (making the air pressure of nitrogen be slightly larger than external atmosphere pressure) usually; Thereby prevent that airborne moisture from getting into enclosure, causes heat-insulating material to freeze to lose heat-insulating property because of making moist.
For the situation that prevents the enclosure nitrogen pressure super-atmospheric pressure far away that atmospheric pressure decline is suddenly caused causes that shell is impaired; The utility model can be provided with more than one superpressure safety valve in cover top portion; When the air pressure of portion and atmospheric difference (being the difference that nitrogen pressure deducts the external atmosphere pressure gained) surpass predetermined safety value in the enclosure; This superpressure safety valve is promptly opened automatically, the excess nitrogen in the shell is discharged fast, thereby prevent that shell is impaired.
More than one breather valve is set on shell, and fills the adsorbent that is used to absorb water in the inside of breather valve.Like this, raise suddenly at external atmospheric pressure, after the air that contains water vapour got into enclosure through breather valve, adsorbent capable of using absorbed these water vapours, thereby avoids moisture to get into enclosure.When the protection nitrogen of portion is through the outside exhaust of breather valve in the enclosure, is adsorbed the moisture that agent absorbs and just is discharged from breather valve again, this is equivalent to the regeneration of adsorbent, thereby the adsorbent in the utility model can recycle for a long time.
The utlity model has following advantage:
(1) the utility model only is provided with an ice chest; After cryogen of low-pressure low-temperature that the cooling of a cryogen cooling subsystem obtains is input to a cryogen cooling duct in this ice chest; Can cool off the cryogen of high normal pressure and temperature in the NG in the NG precooling passage, the cryogen precooling passage, No. two cryogens of high normal pressure and temperature in one section precooling passage of No. two cryogens; Cryogen of the low normal pressure and temperature that obtains behind the released cold quantity is delivered to cryogen external treatment subsystem No. one; With compression and the cooling of carrying out a cryogen, for next step circulation precooling is prepared; After No. two cryogens of low-pressure low-temperature that the cooling of No. two cryogens cooling subsystem obtains are input to No. two cryogen cooling ducts; Can cool off No. two cryogens of temperature in the high pressure in the light hydrocarbon component of gaseous state in the NG deep cooling passage, two sections precooling passages of No. two cryogens; No. two cryogens of the low normal pressure and temperature that obtains behind the released cold quantity are delivered to cryogen external treatment subsystem No. two; With compression and the cooling of carrying out No. two cryogens, for next step circulation deep cooling is prepared.After NG was cooled in NG precooling passage, heavy hydrocarbon component wherein was liquefied, and in the heavy hydrocarbon knockout drum, was in the liquid phase space and was separated, and the light hydrocarbon component of gaseous state is further cooled liquefaction and is LNG in NG deep cooling passage, output in the denitrogenation jar.Therefore; The utility model cryogen capable of using and No. two cryogens carry out cooling liquid to NG in an ice chest; Carry the NG input pipe of NG, cryogen external treatment subsystem, No. two cryogen external treatment subsystems, cryogen cooling subsystem, No. two cryogen cooling subsystems, heavy hydrocarbon knockout drum and denitrogenation jars only need with ice chest on inlet or the outlet of respective channel link to each other and get final product; This has dwindled the volume of ice chest, and has greatly reduced the complexity of this two refrigerants liquefaction system.In addition; Cryogen of low-pressure low-temperature and No. two cryogens of low-pressure low-temperature are when carrying out cooling liquid to NG; Also No. two cryogens of temperature in No. two cryogens of high normal pressure and temperature in the cryogen of high normal pressure and temperature in the cryogen precooling passage, one section precooling passage of No. two cryogens, the high pressure in two sections precooling passages of No. two cryogens are cooled off; Thereby improved the utilization ratio of two kinds of cryogens, and then improved the cooling effectiveness of ice chest, reduced the energy consumption of this system.
(2) ice chest in the utility model can adopt the vacuum brazing aluminum plate-fin heat exchanger to realize; Its inside can be carried out the heat exchange between multiply cold fluid and the multiply hot fluid simultaneously; Satisfied the requirement that the azeotrope refrigeration process cools off and liquefies at different potential temperatures respectively NG; And cryogen and No. two cryogens that NG carries out precooling and deep cooling have respectively all only been carried out the liquefaction that once cooling has promptly realized heavy hydrocarbon component and light hydrocarbon component respectively; Thereby the liquefaction efficiency of the utility model is than higher, and the volume of ice chest is little, and wear life is long.
(3) in the utility model; It is a pipeline that links to each other with cryogen cooling duct that cryogen input pipe of cryogen input pipe of gaseous state low-pressure low-temperature and liquid low-pressure low-temperature converges in the porch of a cryogen cooling duct; The abundant mixing in cryogen cooling duct of this cryogen of low-pressure low-temperature that has just guaranteed the gaseous state that the two is carried respectively and liquid cryogen of low-pressure low-temperature; Gas-liquid in the cryogen cooling duct 13 is distributed rationally; Can carry out the cold exchange better, this has improved the liquefaction efficiency of the utility model to NG.
(4) the utility model successively utilizes aerial cooler and water cooler that every kind of cryogen is cooled off, and has made full use of the cold of atmosphere, has reduced the utilization of recirculated cooling water, has also reduced the energy consumption of the utility model.
(5) the utility model utilizes this heat exchanger that the cold of BOG is discharged the NG that liquefies to needs; Thereby reduced the temperature of the NG that gets into NG precooling passage; Help improving liquefaction efficiency, also made full use of the cold of BOG simultaneously, realized the comprehensive utilization of energy.
(6) the denitrogenation jar in the utility model can realize removing the function of the nitrogen in the NG liquefaction products, and the nitrogen content that satisfies the LNG product is lower than 1% requirement.
Description of drawings
The structure chart that Fig. 1 provides for prior art around the tubular type ice chest;
The structure chart of the still formula ice chest that Fig. 2 provides for prior art;
The structure chart of the liquefaction system of the natural gas that Fig. 3 provides for prior art;
The structure chart of the two refrigerants liquefaction system of the natural gas that Fig. 4 provides for the utility model.
The specific embodiment
Below in conjunction with accompanying drawing the principle and the characteristic of the utility model are described, institute gives an actual example and only is used to explain the utility model, is not the scope that is used to limit the utility model.
The structure chart of the two refrigerants liquefaction system of the natural gas that Fig. 4 provides for the utility model.It is as shown in Figure 4,
The two refrigerants liquefaction system of the described a kind of natural gas of the utility model, this system comprises:
Extracting tower 57, drier 58, mercury deviate from jars 59, dust filter unit 60, BOG cooler 62, compressor 61, heat exchanger 54, cryogen external treatment subsystem, cryogen cooling subsystem 01, No. two cryogen external treatment subsystems, No. two cryogens coolings subsystem 02, heavy hydrocarbon knockout drum 23 and denitrogenation jars 41;
Wherein, cryogen cooling subsystem 01 comprises: NG precooling passage 11, cryogen precooling passage 12, cryogen cooling duct 13 and one section precooling passage 14 of No. two cryogens;
No. two cryogens cooling subsystem 02 comprises: NG deep cooling passage 15, No. two two sections precooling passages 16 of cryogen and No. two cryogen cooling ducts 17;
No. one cryogen external treatment subsystem comprises: cryogen surge tank 63, cryogen compressor 64, cryogen aerial cooler 65, a water as refrigerant cooler 66 and a cryogen knockout drum 20;
No. two cryogen external treatment subsystem comprises: No. two cryogen surge tanks 67, No. two cryogen compressors 68, No. two cryogen aerial coolers 69, No. two water as refrigerant coolers 70 and No. two cryogen knockout drums 36;
Extracting tower 57, drier 58, mercury are deviate from jar 59, dust filter unit 60 connects the back successively and is connected with heat exchanger 54NG pipe input through NG carrier pipe 55; Heat exchanger 54NG pipe output is connected through NG precooling passage 11 inputs of NG carrier pipe 56 with a cryogen cooling subsystem 01; NG precooling passage 11 outputs are connected with heavy hydrocarbon knockout drum 23 through NG carrier pipe 24; Heavy hydrocarbon knockout drum 23 bottoms carry control valve 29 to be connected with heavy hydrocarbon storage tank 30 through heavy hydrocarbon carrier pipe 28, heavy hydrocarbon; Heavy hydrocarbon storage tank 30 passes through heavy hydrocarbon delivery pump 31, heavy hydrocarbon carrier pipe 33 and defeated stop valve 32 outward and is connected with outer defeated heavy hydrocarbon system; Heavy hydrocarbon knockout drum 23 and heavy hydrocarbon are carried between the control valve 29 and are connected with No. two liquid level detectors 26 and No. three controllers; Be connected with No. three liquid level detectors 26 and No. four controllers between heavy hydrocarbon storage tank 30 and the outer defeated stop valve 32; The cryogen surge tank 63 of a cryogen external treatment subsystem, cryogen compressor 64, a cryogen aerial cooler 65 are connected with a water as refrigerant cooler 66 successively; Be connected with the output of a cryogen cooling duct 13 of a cryogen cooling subsystem 01 through a cryogen surge tank 63, be connected with cryogen precooling passage 12 inputs of a cryogen cooling subsystem 01 through a water as refrigerant cooler; No. one cryogen precooling passage 12 outputs are connected with cryogen knockout drum 20 inputs with shutoff valve 19 through pipeline 18, and No. one cryogen knockout drum 20 outputs are connected with the input of liquid phase pipeline 22 with a cryogen cooling duct 13 through gas phase pipeline 21;
NG deep cooling passage 15 inputs of No. two cryogen cooling subsystems 02 are connected with heavy hydrocarbon knockout drum 23 tops through pipeline 25; NG deep cooling passage 15 outputs are connected with denitrogenation jar 41 with pressure-reducing valve 43 through pipeline 42, are connected with controller 44 and pressure gauge 45 between pressure-reducing valve 43 and the denitrogenation jar 41; No. two cryogen precooling passage 16 inputs are connected with one section precooling passage 14 of No. two cryogens of a cryogen cooling subsystem 01; No. two cryogen precooling passage 16 outputs are connected with No. two cryogen knockout drums 36 with valve 38 through pipeline 37, and No. two cryogen knockout drum 36 is connected with No. two cryogen cooling duct 17 inputs with gas phase pipeline 40 through liquid phase pipeline 39; No. two cryogen cooling duct 17 outputs are connected with No. two cryogen surge tank 67 inputs of No. two cryogen external treatment subsystems; After No. two cryogen surge tanks 67 of No. two cryogen external treatment subsystems, No. two cryogen compressors 68, No. two cryogen aerial coolers 69, No. two water as refrigerant coolers 70 connected successively, the output through No. two water as refrigerant coolers 70 was connected with one section precooling passage 14 of No. two cryogens of a cryogen cooling subsystem 01;
Denitrogenation jar 41 bottoms are connected with LNG storage tank 46 through LNG delivery pump 47, LNG control valve 49, pipeline 48; Be connected with a liquid level detector 50 and No. two controllers 51 between LNG storage tank 46 and the LNG control valve 49; LNG storage tank 46 is connected with cold input pipe 523 through tube connector 53; Denitrogenation jar 41 tops are connected with cold input pipe 523 through pipeline 52; Cold input pipe 523 is connected with heat exchanger 54; Heat exchanger 54 is connected with BOG cooler 62 through compressor 61, and BOG cooler 62 connects fuel system.
Claims (5)
1. the two refrigerants liquefaction system of a natural gas, this system comprises: extracting tower (57), drier (58), mercury are deviate from jar (59), a dust filter unit (60), BOG cooler (62), compressor (61), heat exchanger (54), a cryogen external treatment subsystem, a cryogen cooling subsystem (01), No. two cryogen external treatment subsystems, No. two cryogens coolings subsystem (02), heavy hydrocarbon knockout drum (23) and denitrogenation jars (41);
Wherein, a cryogen cooling subsystem (01) comprising: NG precooling passage (11), a cryogen precooling passage (12), a cryogen cooling duct (13) and No. two one section precooling passage of cryogen (14);
No. two cryogen cooling subsystems (02) comprising: NG deep cooling passage (15), No. two two sections precooling passages of cryogen (16) and No. two cryogen cooling ducts (17);
No. one cryogen external treatment subsystem comprises: a cryogen surge tank (63), a cryogen compressor (64), a cryogen aerial cooler (65), a water as refrigerant cooler (66) and a cryogen knockout drum (20);
No. two cryogen external treatment subsystem comprises: No. two cryogen surge tanks (67), No. two cryogen compressors (68), No. two cryogen aerial coolers (69), No. two water as refrigerant coolers (70) and No. two cryogen knockout drums (36); It is characterized in that:
Extracting tower (57), drier (58), mercury are deviate from jar (59), dust filter unit (60) connects the back successively and is connected with heat exchanger (54) NG pipe input through NG carrier pipe (55); Heat exchanger (54) NG pipe output is connected through NG precooling passage (11) input of NG carrier pipe (56) with a cryogen cooling subsystem (01); NG precooling passage (11) output is connected with heavy hydrocarbon knockout drum (23) through NG carrier pipe (24); Heavy hydrocarbon knockout drum (23) bottom carries control valve (29) to be connected with heavy hydrocarbon storage tank (30) through heavy hydrocarbon carrier pipe (28), heavy hydrocarbon; Heavy hydrocarbon storage tank (30) is connected with outer defeated heavy hydrocarbon system through heavy hydrocarbon delivery pump (31), heavy hydrocarbon carrier pipe (33) and outer defeated stop valve (32); Heavy hydrocarbon knockout drum (23) and heavy hydrocarbon are carried between the control valve (29) and are connected with No. two liquid level detectors (26) and No. three controllers; Be connected with No. three liquid level detectors (26) and No. four controllers between heavy hydrocarbon storage tank (30) and the outer defeated stop valve (32); A cryogen surge tank (63) of a cryogen external treatment subsystem, a cryogen compressor (64), a cryogen aerial cooler (65) and a water as refrigerant cooler (66) are connected successively; Be connected through the output of a cryogen surge tank (63), be connected with a cryogen precooling passage (12) input of a cryogen cooling subsystem (01) through a water as refrigerant cooler with a cryogen cooling duct (13) of a cryogen cooling subsystem (01); A cryogen precooling passage (12) output is connected with a cryogen knockout drum (20) input with shutoff valve (19) through pipeline (18), and a cryogen knockout drum (20) output is connected with the input of liquid phase pipeline (22) with a cryogen cooling duct (13) through gas phase pipeline (21);
NG deep cooling passage (15) input of No. two cryogen cooling subsystems (02) is connected with heavy hydrocarbon knockout drum (23) top through pipeline (25); NG deep cooling passage (15) output is connected with denitrogenation jar (41) with pressure-reducing valve (43) through pipeline (42), is connected with a controller (44) and pressure gauge (45) between pressure-reducing valve (43) and the denitrogenation jar (41); No. two cryogen precooling passages (16) input is connected with one section precooling passage of No. two cryogens (14) of a cryogen cooling subsystem (01); No. two cryogen precooling passages (16) output is connected with No. two cryogen knockout drums (36) with valve (38) through pipeline (37), and No. two cryogen knockout drums (36) are connected with No. two cryogen cooling ducts (17) input with gas phase pipeline (40) through liquid phase pipeline (39); No. two cryogen cooling ducts (17) output is connected with No. two cryogen surge tanks (67) input of No. two cryogen external treatment subsystems; After No. two cryogen surge tanks (67) of No. two cryogen external treatment subsystems, No. two cryogen compressors (68), No. two cryogen aerial coolers (69), No. two water as refrigerant coolers (70) connected successively, the output through No. two water as refrigerant coolers (70) was connected with one section precooling passage of No. two cryogens (14) of a cryogen cooling subsystem (01);
Denitrogenation jar (41) bottom is connected with LNG storage tank (46) through LNG delivery pump (47), LNG control valve (49), pipeline (48); Be connected with a liquid level detector (50) and No. two controllers (51) between LNG storage tank (46) and the LNG control valve (49); LNG storage tank (46) is connected with cold input pipe (523) through tube connector (53); Denitrogenation jar (41) top is connected with cold input pipe (523) through pipeline (52); Cold input pipe (523) is connected with heat exchanger (54); Heat exchanger (54) is connected with BOG cooler (62) through compressor (61), and BOG cooler (62) connects fuel system.
2. the two refrigerants liquefaction system of natural gas according to claim 1; It is characterized in that NG precooling passage, a cryogen precooling passage, one section precooling passage of No. two cryogens, a cryogen cooling duct of described cryogen cooling subsystem (01) place a shell; NG deep cooling passage, two sections precooling passages of No. two cryogens, No. two cryogen cooling ducts of described No. two cryogens cooling subsystems (02) place another shell; Be filled with heat-insulating material with passage space each other in the shell.
3. the two refrigerants liquefaction system of natural gas according to claim 2 is characterized in that, said shell is provided with breather valve; The adsorbent that is used to absorb water is filled in the inside of said breather valve.
4. the two refrigerants liquefaction system of natural gas according to claim 2 is characterized in that, the space that said enclosure is filled said heat-insulating material also is filled with the nitrogen of air pressure greater than external atmosphere pressure; Then the top of said shell is provided with more than one superpressure safety valve.
5. the two refrigerants liquefaction system of natural gas according to claim 1; It is characterized in that; NG precooling passage, NG deep cooling passage, a cryogen precooling passage, a cryogen cooling duct, one section precooling passage of No. two cryogens, two sections precooling passages of No. two cryogens, No. two cryogen cooling ducts are the transfer passage of the fluid of the both ends open that fin, flow deflector, dividing plate and strip of paper used for sealing form; Its structure is: in the middle of two dividing plates, place one deck fin; Flow deflector is placed in the front and back of fin, and strip of paper used for sealing is placed in the left and right sides of fin and flow deflector, constitutes the fluid supplying passage of a both ends open.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201120409354 CN202339064U (en) | 2011-10-25 | 2011-10-25 | Double-refrigerant liquefaction system for natural gas |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201120409354 CN202339064U (en) | 2011-10-25 | 2011-10-25 | Double-refrigerant liquefaction system for natural gas |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103075869A (en) * | 2011-10-25 | 2013-05-01 | 中国石油天然气股份有限公司 | Double-refrigerant liquefaction system and method for natural gas |
| CN103343877A (en) * | 2013-07-26 | 2013-10-09 | 武汉钢铁(集团)公司 | Method and system for pre-cooling ethylene storage tank by low temperature nitrogen |
| CN106641715A (en) * | 2016-12-21 | 2017-05-10 | 深圳市燃气集团股份有限公司 | System for recovering BOG (Boil Off Gas) cold from natural gas liquefaction cold box |
| CN110044131A (en) * | 2019-05-06 | 2019-07-23 | 郑州轻工业学院 | A kind of multi-stage compression propane pre-cooling natural gas liquefaction system and its liquifying method |
-
2011
- 2011-10-25 CN CN 201120409354 patent/CN202339064U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103075869A (en) * | 2011-10-25 | 2013-05-01 | 中国石油天然气股份有限公司 | Double-refrigerant liquefaction system and method for natural gas |
| CN103343877A (en) * | 2013-07-26 | 2013-10-09 | 武汉钢铁(集团)公司 | Method and system for pre-cooling ethylene storage tank by low temperature nitrogen |
| CN103343877B (en) * | 2013-07-26 | 2014-12-10 | 武汉钢铁(集团)公司 | Method and system for pre-cooling ethylene storage tank by low temperature nitrogen |
| CN106641715A (en) * | 2016-12-21 | 2017-05-10 | 深圳市燃气集团股份有限公司 | System for recovering BOG (Boil Off Gas) cold from natural gas liquefaction cold box |
| CN110044131A (en) * | 2019-05-06 | 2019-07-23 | 郑州轻工业学院 | A kind of multi-stage compression propane pre-cooling natural gas liquefaction system and its liquifying method |
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