CN204678802U - The device that a kind of rich nitrogen BOG liquefies - Google Patents
The device that a kind of rich nitrogen BOG liquefies Download PDFInfo
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- CN204678802U CN204678802U CN201520317098.3U CN201520317098U CN204678802U CN 204678802 U CN204678802 U CN 204678802U CN 201520317098 U CN201520317098 U CN 201520317098U CN 204678802 U CN204678802 U CN 204678802U
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- bog
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- flash tank
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Abstract
The device that rich nitrogen BOG liquefies, it comprises: BOG compressor, BOG compressor aftercooler, refrigeration machine, BOG cryogenic heat exchanger, LNG/BOG heat exchanger, four choke valves, BOG primary flash tank, BOG two-stage flash tank, nitrogen separation tanks.The device BOG liquefaction flow path that the utility model provides is simple, and cold-producing medium is single, little on original system impact, is specially adapted to the transformation of LNG gas holder station, can adapts to nitrogen content of in BOG about 2% ~ 20%.
Description
Technical field
The utility model provides the device that a kind of rich nitrogen BOG (Boil Off Gas, boil-off gas) liquefies, and the BOG be applicable to LNG storage tank and LNG entrucking, unloading system produce liquefies again.
Background technology
Current China LNG industry is also in period of expansion, it is a comparatively general and phenomenon that BOG diffuses, for the LNG facility of some conveyance vehicles and user's deficiency, year the amount of diffusing often can account for and always buy more than 10% of tolerance, serious even can reach 30%.BOG is liquefied again and effectively can alleviate the problem that LNG gas station and other LNG facility BOG frequently diffuse.Tolerance 10000Nm is added with a design
3the LNG gas station of/d is example, if bleeding rate is that 10%, one year direct economic loss is close to 200,000 yuan.BOG is liquefied avoid this part cost allowance as much as possible again, there is high economy.
In addition, the main component methane of BOG is a kind of typical greenhouse gases, and its greenhouse effects are about 20 times of carbon dioxide.Releasing of BOG not only wastes energy, and brings the risk of gas fuel burning, blast, causes serious greenhouse effects, contaminated environment simultaneously, runs in the opposite direction with the object of planning of China protection of the environment, energy-saving and emission-reduction, sustainable development.
What current BOG liquefaction application was more is that BOG enters ice chest after compressor supercharging, liquefy under the refrigeration of the cold-producing medium in ice chest, this technique has certain dependence to original natural gas liquefaction system, especially when the amount variation of BOG is larger, the easy stability affecting natural gas in ice chest-refrigerant heat exchanger system, and need to increase special BOG heat exchange runner, therefore the structure of ice chest is comparatively complicated.Simultaneously as higher in nitrogen content, also will apply rectifying column, flow process and operation are all complicated.
Utility model content
The utility model proposes the device that a kind of rich nitrogen BOG liquefies, it comprises: BOG compressor, BOG compressor aftercooler, refrigeration machine, BOG cryogenic heat exchanger, LNG/BOG heat exchanger, four choke valves, BOG primary flash tank (a BOG flash tank), BOG two-stage flash tank (the 2nd BOG flash tank), nitrogen separation tanks;
The external BOG pipeline in battery limit (BL) connects low temperature BOG successively and is connected to BOG suction port of compressor after heat exchanger, after BOG compressor outlet is connected to BOG compressor aftercooler, refrigeration machine, BOG cryogenic heat exchanger successively, be connected to first throttle valve inlet, the outlet of first throttle valve connects BOG primary flash tank entrance, the gas phase port of BOG primary flash tank is connected to nitrogen separation tank through LNG/BOG heat exchanger, BOG primary flash tank liquid phase port connects second throttle, is connected to BOG two-stage flash tank entrance by LNG/BOG heat exchanger, the 3rd choke valve; Nitrogen separation tank top is provided with rich nitrogen outlet, and bottom liquid phases port is connected to BOG two-stage flash tank entrance after the 4th choke valve; The external BOG ducts converge of BOG two-stage flash tank gaseous phase outlet pipeline and battery limit (BL), liquid-phase outlet is connected to LNG stocking system.
BOG compressor adopts one or two depending on the form of compressor.
Preferably, the device that rich nitrogen BOG of the present invention liquefies comprises BOG normal temperature heat exchanger further between BOG compressor aftercooler and refrigeration machine, the external BOG pipeline in battery limit (BL) connects low temperature BOG heat exchanger, normal temperature BOG is connected to BOG suction port of compressor after heat exchanger, and BOG compressor outlet is connected to BOG compressor aftercooler, BOG normal temperature heat exchanger, refrigeration machine, BOG cryogenic heat exchanger successively.
The technique using the rich nitrogen BOG of said apparatus to liquefy comprises:
First the low-temperature atmosphere-pressure BOG being rich in nitrogen from LNG storage tank or LNG entrucking, unloading system enters in BOG cryogenic heat exchanger and reclaims cold energy, with the high pressure BOG heat exchange re-heat after BOG compressor boost to-20 ~-45 DEG C (such as-35 DEG C), then optionally enter re-heat to 15 ~ 25 DEG C in BOG normal temperature heat exchanger, such as 20 DEG C;
BOG after re-heat is cooled to about 30 ~ 45 DEG C after BOG compressor boost to 10 ~ 25MPaA (such as 20MPaA) in compressor aftercooler, such as 40 ~ 45 DEG C, then be chilled to-85 ~-150 DEG C (such as-85 ~-120 DEG C in advance through BOG normal temperature heat exchanger, refrigeration machine and BOG cryogenic heat exchanger successively, or-105 DEG C or-120 DEG C), finally enter First choke valve throttling to 0.8 ~ 2.5MPaA (such as 1.5MPaA), after utilizing first precooling, most of BOG liquefies by the principle of high pressure throttling refrigeration;
Logistics after throttling enters in BOG primary flash tank (such as at 1.0-2.0MPaA, especially flash distillation under 1.5MPaA), tank top obtains the BOG being rich in nitrogen, the flow process that this technique adopts by the LNG that obtains at the bottom of tank through second throttle throttling to 0.1 ~ 0.8MPaA (such as 0.5MPaA), the methane component liquefaction of the overwhelming majority in BOG primary flash tank tank deck BOG is reclaimed by the cold utilizing its throttling to produce, this process is carried out in LNG/BOG heat exchanger, obtain rich nitrogen and LNG, rich nitrogen separates in nitrogen separation tank, the LNG that nitrogen separation pot bottom obtains is through the 4th choke valve throttling to 0.1 ~ 0.8MPaA (such as 0.15MPaA), with logistics (pressure regulation to the 0.1 ~ 0.8MPaA of the LNG from LNG/BOG heat exchanger after the 3rd choke valve pressure regulation, with pressure match after the 4th choke valve) converge, then enter in BOG two-stage flash tank (such as at 0.10-0.20MPaA, especially flash distillation under 0.15MPaA) isolate BOG, BOG loops back BOG cryogenic heat exchanger entrance and liquefies, LNG and deliver to LNG stocking system.In product LNG, nitrogen content is less than 1%.
High pressure BOG is chilled in advance 0 ~ 30 DEG C (such as 5 DEG C ~ 25 DEG C) after BOG normal temperature heat exchanger, is chilled in advance-15 ~-45 DEG C (such as-20 ~-40 DEG C) after refrigeration machine.
The cold-producing medium that refrigeration machine adopts can be one or more in propane, propylene, freon etc.
BOG compressor aftercooler adopts circulating water, and the cooling system of air cooling or other equivalences also can be adopted to replace.
During BOG compressor employing cryogenic compressor, can not have BOG normal temperature heat exchanger in flow process, low temperature BOG directly enters BOG compressor boost.That is, BOG compressor is cryogenic compressor, and directly enter BOG compressor from BOG cryogenic heat exchanger BOG out and compress, without BOG normal temperature heat exchanger, and cooled BOG directly enters in refrigeration machine in compressor aftercooler.The BOG liquefaction flow path that technique of the present utility model provides is simple, and cold-producing medium is single, little on original system impact, be specially adapted to the transformation of LNG gas holder station, and the nitrogen content of the BOG that can adapt to is wider, about 2% ~ 20%.
BOG cryogenic heat exchanger and BOG normal temperature heat exchanger are that the low-temperature space that flows through according to BOG and high-temperature region divide.
MPaA represents absolute pressure.
Advantage of the present utility model:
1, the liquefaction flow path of BOG is relatively independent, little to stoste systematic influence, and the fluctuation of BOG flow can not affect the normal operating of ice chest;
2, whole flow process heat exchange is reasonable, and BOG cold is recycled utilization;
3, refrigeration machine adopts unitary system cryogen can realize operation, there is not the problem of cold-producing medium proportioning;
4, wider nitrogen content scope can be adapted to, and in product LNG, nitrogen content is less than 1%.
Accompanying drawing explanation
Fig. 1 is installation diagram of the present utility model.
Wherein, C-1, BOG compressor E-1, compressor aftercooler E-2, BOG normal temperature heat exchanger E-3, refrigeration machine E-4, BOG cryogenic heat exchanger E-5, LNG/BOG heat exchanger V-1, BOG primary flash tank V-2, nitrogen separation tank V-3, BOG two-stage flash tank X-1, first throttle valve X-2, second throttle X-3, the 3rd choke valve X-4, the 4th choke valve
Detailed description of the invention
The utility model proposes the device that a kind of rich nitrogen BOG liquefies.With reference to accompanying drawing 1, its device comprises BOG compressor C-1 and BOG compressor aftercooler E-1, a BOG normal temperature heat exchanger E-2, a refrigeration machine E-3, a BOG cryogenic heat exchanger E-4, a LNG/BOG heat exchanger E-5, four choke valves X-1, X-2, X-4, two BOG flash tank V-1, V-3 (a BOG flash tank and the 2nd BOG flash tank) and a nitrogen separation tank V-2; BOG compressor C-1 adopts one or two depending on the form of compressor;
The external BOG pipeline in battery limit (BL) connects low temperature BOG heat exchanger E-4 successively, BOG compressor C-1 entrance is connected to after normal temperature BOG heat exchanger E-2, BOG compressor C-1 outlet is connected to BOG compressor aftercooler E-1 successively, BOG normal temperature heat exchanger E-2, refrigeration machine E-3, after BOG cryogenic heat exchanger E-4, be connected to first throttle valve X-1 entrance, the outlet of first throttle valve X-1 connects BOG primary flash tank V-1 entrance, the gas phase port of BOG primary flash tank V-1 is connected to nitrogen separation tank V-2 through LNG/BOG heat exchanger E-5, BOG primary flash tank V-1 liquid phase port connects second throttle X-2, by LNG/BOG heat exchanger E-5, 3rd choke valve X-3 is connected to BOG two-stage flash tank V-3 entrance, nitrogen separation tank V-2 top is provided with rich nitrogen outlet, and bottom liquid phases port is connected to BOG two-stage flash tank V-3 entrance after the 4th choke valve X-4, the external BOG ducts converge of BOG two-stage flash tank V-3 gaseous phase outlet pipeline and battery limit (BL), liquid-phase outlet is connected to LNG stocking system.
The utility model also proposes the technique that a kind of rich nitrogen BOG liquefies.With reference to accompanying drawing 1, its technical process is:
First the low-temperature atmosphere-pressure BOG being rich in nitrogen from LNG storage tank or LNG entrucking, unloading system enters in BOG cryogenic heat exchanger E-4 and reclaims cold energy, with the high pressure BOG heat exchange re-heat after BOG compressor C-1 supercharging to-20 ~-45 DEG C (such as-35 DEG C), then optionally enter re-heat to 15 ~ 25 DEG C (such as 20 DEG C) in BOG normal temperature heat exchanger E-2;
BOG after re-heat is pressurized to after 10 ~ 25MPaA (such as 20MPaA) through BOG compressor C-1 in compressor aftercooler E-1, is cooled to about 30 ~ 45 DEG C, such as 40 ~ 45 DEG C, then be chilled in advance about-85 ~-150 DEG C (such as-105 DEG C or-120 DEG C) through optional BOG normal temperature heat exchanger E-2, refrigeration machine E-3 and BOG cryogenic heat exchanger E-4 successively, finally enter First choke valve X-1 throttling to 0.8 ~ 2.5MPaA (such as 1.5MPaA), after utilizing first precooling, most of BOG liquefies by the principle of high pressure throttling refrigeration;
Logistics after throttling enters in BOG primary flash tank V-1 (such as flash distillation under 1.5MPaA), nitrogen is rich in the BOG that tank top obtains, this technique adopt flow process by LNG at the bottom of tank through second throttle X-2 throttling to 0.1 ~ 0.8MPaA (such as 0.15MPaA or such as 0.5MPaA), the methane component liquefaction of the overwhelming majority in BOG primary flash tank V-1 tank deck BOG is reclaimed by the cold utilizing its throttling to produce, this process is carried out in LNG/BOG heat exchanger E-5, create rich nitrogen and LNG, rich nitrogen separates in nitrogen separation tank V-2, LNG bottom nitrogen separation tank V-2 is through the 4th choke valve X-4 throttling to 0.1 ~ 0.8MPaA (such as 0.15MPaA), with logistics (pressure regulation to the 0.1 ~ 0.8MPaA of LNG after the 3rd choke valve X-3 pressure regulation from LNG/BOG heat exchanger E-5, with pressure match after the 4th choke valve) converge, then enter (such as flash distillation under 0.15MPaA) in BOG two-stage flash tank V-2 and isolate BOG, BOG loops back entrance and liquefies, LNG and deliver to LNG stocking system.In product LNG, nitrogen content is less than 1%.
High pressure BOG is chilled to 0 ~ 30 DEG C in advance after BOG normal temperature heat exchanger E-2, such as 0 ~ 20 DEG C, after refrigeration machine E-3, is chilled to-15 ~-45 DEG C in advance.
The cold-producing medium that refrigeration machine E-3 adopts can be one or more in propane, propylene, freon etc.
BOG compressor aftercooler E-1 adopts circulating water, and the cooling system of air cooling or other equivalences also can be adopted to replace.
During BOG compressor C-1 employing cryogenic compressor, BOG normal temperature heat exchanger E-2 can not had in flow process, (namely low temperature BOG directly enters BOG compressor C-1 supercharging, directly enter BOG compressor C-1 from BOG cryogenic heat exchanger E-4 BOG out and compress, without BOG normal temperature heat exchanger E2), in compressor aftercooler E-1, cooled BOG directly enters in refrigeration machine E-3.
The BOG liquefaction flow path that technique of the present utility model provides is simple, and cold-producing medium is single, little on original system impact, be specially adapted to the transformation of LNG gas holder station, and the nitrogen content of the BOG that can adapt to is wider, about 2% ~ 20%.
Claims (3)
1. a device for rich nitrogen BOG liquefaction, it comprises: BOG compressor, BOG compressor aftercooler, refrigeration machine, BOG cryogenic heat exchanger, LNG/BOG heat exchanger, four choke valves, BOG primary flash tank, BOG two-stage flash tank, nitrogen separation tanks;
The external BOG pipeline in battery limit (BL) connects low temperature BOG successively and is connected to BOG suction port of compressor after heat exchanger, after BOG compressor outlet is connected to BOG compressor aftercooler, refrigeration machine, BOG cryogenic heat exchanger successively, be connected to first throttle valve inlet, the outlet of first throttle valve connects BOG primary flash tank entrance, the gas phase port of BOG primary flash tank is connected to nitrogen separation tank through LNG/BOG heat exchanger, BOG primary flash tank liquid phase port connects second throttle, is connected to BOG two-stage flash tank entrance by LNG/BOG heat exchanger, the 3rd choke valve; Nitrogen separation tank top is provided with rich nitrogen outlet, and bottom liquid phases port is connected to BOG two-stage flash tank entrance after the 4th choke valve; The external BOG ducts converge of BOG two-stage flash tank gaseous phase outlet pipeline and battery limit (BL), liquid-phase outlet is connected to LNG stocking system.
2. the device of rich nitrogen BOG liquefaction according to claim 1, wherein, BOG compressor adopts one or two.
3. the device of rich nitrogen BOG liquefaction according to claim 1 and 2, it comprises BOG normal temperature heat exchanger further between BOG compressor aftercooler and refrigeration machine, the external BOG pipeline in battery limit (BL) connects low temperature BOG heat exchanger, normal temperature BOG is connected to BOG suction port of compressor after heat exchanger, and BOG compressor outlet is connected to BOG compressor aftercooler, BOG normal temperature heat exchanger, refrigeration machine, BOG cryogenic heat exchanger successively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520317098.3U CN204678802U (en) | 2015-05-15 | 2015-05-15 | The device that a kind of rich nitrogen BOG liquefies |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520317098.3U CN204678802U (en) | 2015-05-15 | 2015-05-15 | The device that a kind of rich nitrogen BOG liquefies |
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| CN204678802U true CN204678802U (en) | 2015-09-30 |
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| CN201520317098.3U Withdrawn - After Issue CN204678802U (en) | 2015-05-15 | 2015-05-15 | The device that a kind of rich nitrogen BOG liquefies |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104913594A (en) * | 2015-05-15 | 2015-09-16 | 新地能源工程技术有限公司 | Nitrogen-rich BOG liquefying technology and device |
| CN111344528A (en) * | 2017-11-21 | 2020-06-26 | 乔治洛德方法研究和开发液化空气有限公司 | BOG recondenser and LNG supply system provided with same |
| US11561042B2 (en) | 2016-02-26 | 2023-01-24 | LGE IP Management Company Limited | Method of cooling boil-off gas and apparatus therefor |
| US11578914B2 (en) | 2017-04-20 | 2023-02-14 | LGE IP Management Company Limited | Method of cooling boil-off gas and apparatus therefor |
-
2015
- 2015-05-15 CN CN201520317098.3U patent/CN204678802U/en not_active Withdrawn - After Issue
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104913594A (en) * | 2015-05-15 | 2015-09-16 | 新地能源工程技术有限公司 | Nitrogen-rich BOG liquefying technology and device |
| CN104913594B (en) * | 2015-05-15 | 2017-09-22 | 新地能源工程技术有限公司 | A kind of rich liquefied techniques of nitrogen BOG and device |
| US11561042B2 (en) | 2016-02-26 | 2023-01-24 | LGE IP Management Company Limited | Method of cooling boil-off gas and apparatus therefor |
| US11578914B2 (en) | 2017-04-20 | 2023-02-14 | LGE IP Management Company Limited | Method of cooling boil-off gas and apparatus therefor |
| CN111344528A (en) * | 2017-11-21 | 2020-06-26 | 乔治洛德方法研究和开发液化空气有限公司 | BOG recondenser and LNG supply system provided with same |
| CN111344528B (en) * | 2017-11-21 | 2022-02-01 | 乔治洛德方法研究和开发液化空气有限公司 | BOG recondenser and LNG supply system provided with same |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20150930 Effective date of abandoning: 20170922 |
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| AV01 | Patent right actively abandoned |