CN211232396U - Liquefied natural gas LNG system of unloading - Google Patents
Liquefied natural gas LNG system of unloading Download PDFInfo
- Publication number
- CN211232396U CN211232396U CN201921161284.7U CN201921161284U CN211232396U CN 211232396 U CN211232396 U CN 211232396U CN 201921161284 U CN201921161284 U CN 201921161284U CN 211232396 U CN211232396 U CN 211232396U
- Authority
- CN
- China
- Prior art keywords
- lng
- unloading
- bog
- air
- recovery system
- 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.)
- Active
Links
Images
Landscapes
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The utility model provides a liquefied natural gas LNG system of unloading, this system includes: LNG tank cars; the LNG unloading arm is connected with the LNG tank wagon; an LNG storage tank; the LNG cryogenic pump is connected with the LNG storage tank; the BOG recovery system is connected with the LNG unloading arm; the air temperature gasifier is connected with the BOG recovery system; compared with the prior art, the invention has the following improvements: the LNG cryogenic pump directly pumps the LNG in the LNG tank wagon through an LNG unloading arm, is connected with the LNG storage tank, and directly conveys the LNG in the tank wagon to the LNG storage tank for storage. The problem that an existing LNG unloading system is too complex to operate is solved on the premise of reducing safety risks, BOG is fully recycled, and maintenance cost of an LNG receiving device is reduced.
Description
Technical Field
The invention relates to an unloading system for Liquefied Natural Gas (LNG), in particular to a BOG recovery technology in the unloading system for the LNG.
Background
Liquefied Natural Gas (LNG) is a high-quality energy source with high calorific value and little combustion pollution. The LNG receiving system is used for unloading and storing LNG after purchasing the LNG, and has the main functions of receiving the LNG, regasifying the LNG when a peak-shaving long-distance transmission pipe network is short of gas, and conveying the natural gas to users through a pipeline.
In the prior art, the LNG receiving technology has two unloading modes. The first method is that flash vapor (BOG) generated in the transportation process of a tank car is used for providing pressure, and LNG in the tank car is conveyed to a storage tank for storage; the second is the gravity flow of LNG by using a height difference from the storage tank. After unloading is completed, a large amount of flash steam (BOG) can be reserved in the tank car, the BOG is conveyed to the storage tank through the gas-phase recovery pipeline to be pressurized to the low-pressure pipe network, and the tank car is subjected to flat pressure by using the volume space of the storage tank in the process. In the prior art, the liquid levels of a storage tank and a tank car in the LNG receiving process need to be strictly monitored; the pressure of the tank car is unstable in the unloading process, the tank car cannot be continuously received for a long time, and the unloading time is long; the flat pressure of the storage tank can cause the temperature in the storage tank to rise and flash steam to increase, thereby generating potential safety hazard; the BOG generated in the tank car in the unloading process can not be completely recovered by utilizing the storage tank for flat pressing; if the low-pressure pipe network is separately transported, the cost will be increased, and a compressor is additionally arranged.
The technical problem solved by the invention is to provide an unloading system for liquefied natural gas LNG, which can solve the problems that the operation of the existing LNG unloading system is too complicated, BOG is fully recycled and utilized, and the maintenance cost of an LNG receiving device is reduced on the premise of reducing safety risks.
Disclosure of Invention
In order to solve the defects in the prior art, the technical scheme is as follows:
a liquefied natural gas LNG unloading system, comprising: the system comprises an LNG tank car, an LNG unloading arm, an LNG storage tank, an LNG cryogenic pump, a BOG recovery system and an air temperature gasifier; the LNG tank wagon is used as a starting point and is connected to the LNG storage tank through the LNG unloading arm and the LNG low-temperature pump in sequence;
the LNG unloading arm is also connected to the air-temperature gasifier through a liquid pipeline;
the LNG cryogenic pump is also connected to the air temperature gasifier;
the air temperature gasifier is also connected to the BOG recovery system;
the LNG storage tank is also connected to the BOG recovery system through a gas phase pipeline;
the BOG recovery system is connected to the LNG unloading arm through a gaseous pipeline.
Further, each line connected to the LNG cryopump includes a check valve for preventing backflow of the transferred LNG.
Further, the pipeline of the air temperature gasifier connected to the BOG recovery system is provided with a hand valve and a one-way valve, and the hand valve and the one-way valve are respectively used for controlling the amount of LNG entering the air temperature gasifier through the BOG recovery system and preventing natural gas in the air temperature gasifier from flowing backwards.
Further, the gas line of the BOG recovery system connected to the LNG unloading arm has a hand valve for flat pressing of the LNG tanker.
Further, the line connecting the LNG unloading arm to the air-temperature vaporizer has a hand valve for controlling the amount of LNG entering the air-temperature vaporizer through the LNG unloading arm.
The utility model has the advantages that:
1. in the invention, the LNG tank wagon is connected with the LNG cryogenic pump, the air-temperature vaporizer, the LNG storage tank and the BOG compressor through the unloading arm to form an LNG gas-liquid conversion circulation line, and BOG volatilized by the storage tank is fully recycled, i.e. the BOG does not need to be discharged into the air, thereby avoiding energy waste and environmental pollution;
2. according to the invention, the BOG flashed out from the storage tank is utilized, so that the pressure in the unloading operation process is improved, the unloading efficiency is improved, and the operation cost of the LNG unloading system is indirectly reduced; meanwhile, accidents such as damage of an LNG storage tank and an LNG tank car, BOG leakage and explosion are prevented;
3. the LNG unloading system provided by the invention can improve the integral temperature of LNG in winter at the peak time of LNG unloading, thereby reducing the heat required during gasification peak regulation and reducing the operation cost of gasification peak regulation;
4. the LNG unloading system provided by the invention is flexible to operate, simple and reliable, has a good use effect, is low in operation cost and has good economic benefits.
Drawings
Fig. 1 is a connection diagram of an unloading system for liquefied natural gas LNG according to the present invention;
fig. 2 is a flow chart illustrating an actual operation of an unloading system for liquefied natural gas LNG according to the present invention;
201-LNG tank car; 202-LNG unloading arm; 203-LNG storage tank; 204-LNG cryogenic pump; 205-BOG recovery system; 206-air temperature vaporizer.
Detailed Description
The following description will further describe embodiments of the present invention with reference to the accompanying drawings and examples.
The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention. On the contrary, the embodiments of the invention include all changes, modifications and equivalents coming within the spirit and terms of the claims appended hereto.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected," "connecting," and "connecting" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Example one
As shown in fig. 1, a LNG unloading system includes: an LNG tank wagon 201, an LNG unloading arm 202, an LNG storage tank 203, an LNG cryogenic pump 204, a BOG recovery system 205 and an air temperature vaporizer 206; the method is characterized in that: with the LNG tanker 201 as a starting point, the LNG tanker 201 is connected to the LNG storage tank 203 sequentially through the LNG unloading arm 202 and the LNG cryogenic pump 204;
the LNG unloading arm 202 is further connected to the air-temperature vaporizer 206 through a liquid line;
the LNG cryogenic pump 204 is also connected to an air temperature vaporizer 206;
the air temperature gasifier 206 is also connected to the BOG recovery system 205;
the LNG storage tank 203 is further connected to the BOG recovery system 205 through a gas phase pipeline;
the BOG recovery system 205 is connected to the LNG unloader arm 202 via a gas line.
Therefore, the BOG flashed out from the storage tank can be utilized, the pressure in the unloading operation process is improved, the unloading efficiency is improved, and the operation cost of the LNG unloading system is indirectly reduced; meanwhile, accidents such as damage of an LNG storage tank and an LNG tank car, BOG leakage and explosion are prevented;
further, each line connected to the LNG cryopump 204 includes a check valve for preventing backflow of the LNG being transferred.
Further, the pipeline connecting the air temperature vaporizer 206 to the BOG recovery system 205 has a hand valve and a check valve for controlling the amount of LNG entering the air temperature vaporizer 206 through the BOG recovery system 205 and preventing the natural gas in the air temperature vaporizer 206 from flowing backward.
Further, the gas line connecting the BOG recovery system 205 to the LNG unloading arm 202 has a hand valve for the flat pressure of the LNG tanker 201.
Further, the line connecting the LNG unloading arm 202 to the air temperature vaporizer 206 has a hand valve for controlling the amount of LNG entering the air temperature vaporizer 206 through the LNG unloading arm 202.
Therefore, an LNG gas-liquid conversion circulation line is formed, BOG volatilized by the storage tank is fully recycled, namely the BOG does not need to be discharged into the air, and therefore energy waste and environmental pollution are avoided
Example two
In the actual working process:
as shown in fig. 2, the system includes a tanker 201 that ships LNG; an LNG unloading arm 202 connected to the LNG tanker 201; a storage tank 203 for storing LNG; an LNG cryogenic pump 204 connected to the storage tank 203; a BOG recovery system 205 that is the same as the LNG tanker 201 in vapor phase space to recover BOG outputted therefrom; an air temperature gasifier 206 connected to the BOG recovery system 205; the LNG unloading arm 202 is a device for unloading LNG in the LNG tanker 201, and includes two pipelines, one of which is a gas pipeline and is connected to the BOG recovery system 205; one is a liquid line that is connected to the LNG cryopump 204.
The LNG cryogenic pump 204 is a liquid pipeline connected to the LNG unloading arm 202 to pressurize LNG in the LNG tank 201 to 0.6MPaG, and has a horizontal cryogenic pump as a main body, and converts energy to 60m LNG for the LNG tank 201 to deliver3The flow rate/h is exported to the LNG storage tank 203 for storage. In addition, in order to prevent the LNG cryogenic pump 204 shown in fig. 2 from malfunctioning and thus causing damage to the unloading system provided by the present invention, a breaking valve is further provided at the inlet, and when the LNG cryogenic pump 204 malfunctions, the breaking valve is immediately activated and the L is stoppedAnd the NG unloading system operates to prevent equipment from being damaged and leakage accidents from being caused.
Here, the LNG tank 201 is a facility for shipping LNG, which is a liquid substance and is located in a lower space of the LNG tank 201, and the gaseous BOG volatilized during the shipping process is concentrated in an upper space inside the LNG tank 201, which is a gas phase space of the LNG tank 201.
The pressure of the gas phase space of the LNG tank wagon 201 is usually 0.3-0.6 MPaG, and the pressure is gradually reduced along with the increase of the gas phase space at the upper part in the unloading process, so that the LNG tank wagon 201 and the LNG cryogenic pump 204 need to be pressurized in time to prevent damage. Therefore, the BOG recovery system 205 needs to input BOG to the LNG tanker 201 connected to the LNG unloading arm 202 in real time to maintain the gas pressure in the gas phase space at 0.3 to 0.6 MPaG.
In the present invention, the air temperature vaporizer 206 vaporizes and pressurizes LNG delivered from the LNG tanker 201 by the LNG unloading arm 202, and the heat source for vaporization is air. Thus, the air temperature vaporizer 206 is a heat exchanger that transfers heat from the air to the LNG, thereby vaporizing the LNG into BOG without cooling. The air temperature vaporizer 206 delivers the BOG obtained by vaporization to the BOG recovery system 204, and inputs the BOG to the LNG tanker 201 in real time through a pipeline, thereby ensuring stable gas pressure in a gas phase space. The air temperature vaporizer 206 provided by the present invention has a vaporization capacity of 200Nm3H is used as the reference value. In addition, in order to control the pressure of the gas phase space of the LNG tanker 201, a manual regulating valve is additionally arranged in front of the air-temperature vaporizer 206 and used for controlling the flow rate of the LNG entering the air-temperature vaporizer 206 from the LNG tanker 201, so that the pressure of the LNG tanker 201 is ensured to be stable, and accidents caused by negative pressure or overpressure are avoided.
The LNG temperature is about-140 to-162.5 ℃ and the BOG temperature is about-120 to 140 ℃ during the LNG transportation, so the LNG tanker 201, the LNG unloading arm 202, the storage tank 203 for storing LNG, the LNG cryogenic pump 203 connected to the storage tank 202, the BOG recovery system 204, the air temperature vaporizer 205, and the pipelines for transporting LNG and BOG are all made of low temperature resistant materials, such as low temperature resistant 9 nickel steel and low temperature stainless steel.
The invention also provides a technical method of the LNG unloading system, which is based on the LNG unloading system shown in the figure 2. The method comprises the following steps:
in addition, on the basis of the technical scheme, the invention can be further improved as follows:
step 1: the LNG cryogenic pump conveys the pressurized LNG to the air-temperature vaporizer through a pipeline so as to increase the gasification amount.
In the invention, the BOG recovery system is used for providing pressure to the gas phase space of the LNG tank car, if the pressure of the gas phase space is too low, the unloading efficiency is low, and the operation speed is slow, so that the pressure of the gas phase space needs to be maintained in real time to keep the gas pressure of the gas phase space to be maintained at 0.3-0.6 MPaG.
Step 2: the air temperature type gasifier takes air as a heat source, LNG after increment is gasified into BOG, and input to a BOG recovery system is increased, so that the gas phase space pressure of an LNG tank car is improved, and the unloading efficiency is improved.
In the invention, the gasification capacity of the air-temperature type gasifier is improved to 800Nm3And h, increasing the LNG flow rate entering the air-temperature gasifier by increasing a pipeline between the LNG low-temperature pump outlet and the air-temperature gasifier inlet, and increasing the BOG amount at the air-temperature gasifier outlet to meet the gas phase space pressure requirement.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.
Claims (5)
1. A liquefied natural gas LNG unloading system, comprising: the LNG tank wagon (201), the LNG unloading arm (202), the LNG storage tank (203), the LNG cryogenic pump (204), the BOG recovery system (205) and the air temperature gasifier (206); the method is characterized in that: the LNG tanker (201) is connected to the LNG storage tank (203) by the LNG unloading arm (202) and the LNG cryogenic pump (204) in sequence, with the LNG tanker (201) as a starting point;
the LNG unloading arm (202) is also connected to the air temperature gasifier (206) through a liquid pipeline;
the LNG cryogenic pump (204) is also connected to an air temperature vaporizer (206);
the air temperature gasifier (206) is also connected to the BOG recovery system (205);
the LNG storage tank (203) is also connected to the BOG recovery system (205) through a gas phase pipeline;
the BOG recovery system (205) is connected to the LNG unloading arm (202) by a gas line.
2. LNG offloading system according to claim 1, characterized in that the lines connected to the LNG cryogenic pump (204) comprise one-way valves for preventing backflow of the delivered LNG.
3. The LNG unloading system of claim 1, wherein the pipeline connecting the air-temperature vaporizer (206) to the BOG recovery system (205) has a hand valve and a check valve for controlling the amount of LNG entering the air-temperature vaporizer (206) through the BOG recovery system (205) and preventing the natural gas in the air-temperature vaporizer (206) from flowing backward.
4. LNG unloading system according to claim 1, characterized in that the gas line of the BOG recovery system (205) connected to the LNG unloading arm (202) has a hand valve for the flat pressure of the LNG tanker (201).
5. The LNG unloading system of claim 1, wherein the pipeline connecting the LNG unloading arm (202) to the air-temperature vaporizer (206) has a hand valve for controlling the amount of LNG entering the air-temperature vaporizer (206) through the LNG unloading arm (202).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921161284.7U CN211232396U (en) | 2019-07-17 | 2019-07-17 | Liquefied natural gas LNG system of unloading |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921161284.7U CN211232396U (en) | 2019-07-17 | 2019-07-17 | Liquefied natural gas LNG system of unloading |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211232396U true CN211232396U (en) | 2020-08-11 |
Family
ID=71931511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921161284.7U Active CN211232396U (en) | 2019-07-17 | 2019-07-17 | Liquefied natural gas LNG system of unloading |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211232396U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113591624A (en) * | 2021-07-16 | 2021-11-02 | 青岛新奥胶南燃气有限公司 | LNG unloading risk prediction method and evaluation system based on statistical analysis |
-
2019
- 2019-07-17 CN CN201921161284.7U patent/CN211232396U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113591624A (en) * | 2021-07-16 | 2021-11-02 | 青岛新奥胶南燃气有限公司 | LNG unloading risk prediction method and evaluation system based on statistical analysis |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102656084B (en) | An lng fuel tank system for at least one gas engine used for ship propulsion | |
| US6460350B2 (en) | Vapor recovery system using turboexpander-driven compressor | |
| CN107076358A (en) | A kind of BOG accumulation of energys pressure difference LNG gas stations | |
| CN107676623B (en) | Differential pressure type LNG filling system | |
| CN113007596A (en) | Hydrogen filling system and hydrogenation station | |
| CN205014033U (en) | BOG energy storage pressure differential LNG gas station | |
| CN111928109A (en) | Boil-off gas recovery system of hydrogenation station | |
| CN104456071A (en) | Liquefied natural gas tanker unloading device and method | |
| CN104006295A (en) | Method and apparatus for displacement type pressure conveying of low-temperature liquefied gas | |
| KR102560637B1 (en) | A method for transporting a cryogenic fluid and a transport system for implementing the method | |
| CN104165266B (en) | A kind of pressure reduction formula liquefied natural gas filling station adds injection system and method thereof | |
| CN105179930A (en) | Liquefied natural gas tank car unloading device of liquefied natural gas and compressed natural gas cooperative station and application | |
| CN211232396U (en) | Liquefied natural gas LNG system of unloading | |
| KR101059869B1 (en) | Regasification Facility of LNG | |
| CN108953988B (en) | Liquid hydrogen vaporization and self-pressurization device | |
| CN104763875A (en) | Liquid unloading method for liquefied natural gas or coal gas | |
| CN107061987B (en) | Filling platform is stored to portable LNG receiving station | |
| CN209819213U (en) | Driving system of low-temperature liquid ammonia storage tank | |
| CN207394353U (en) | A kind of differential LNG tank cars charging system | |
| CN108626568B (en) | Low-energy-consumption LNG (liquefied Natural gas) filling system with BOG (boil off gas) recycling function and filling method | |
| RU127166U1 (en) | GAS FILLING STATION | |
| CN215569758U (en) | Boil-off gas recovery system based on cold energy utilization in LNG receiving station | |
| CN213322836U (en) | Tank truck | |
| CN212298527U (en) | Boil-off gas recovery system of hydrogenation station | |
| CN113203046A (en) | Boil-off gas recovery system and method based on cold energy utilization in LNG receiving station |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |