CN216520911U - Tank car residual gas recovery system for LNG receiving station - Google Patents
Tank car residual gas recovery system for LNG receiving station Download PDFInfo
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- CN216520911U CN216520911U CN202120772140.6U CN202120772140U CN216520911U CN 216520911 U CN216520911 U CN 216520911U CN 202120772140 U CN202120772140 U CN 202120772140U CN 216520911 U CN216520911 U CN 216520911U
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Abstract
The utility model relates to a tank car residual gas recovery system for an LNG receiving station, which comprises: the system comprises an unloading system, a pressure control and metering system, a nitrogen purging system and an emptying system. The method comprises the following steps of connecting a tank car gas phase port with a residual gas recovery system in a hard connection mode, controlling the pressure of the system in an automatic pressure regulation mode, controlling the pressure of the LNG tank car after residual gas recovery to be about 0.2MPag, automatically stopping residual gas recovery when the pressure reaches a set value, triggering an alarm when overpressure occurs, cutting off the recovery system by a parallel lock, ensuring certain residual pressure of the LNG tank car, and recovering BOG residual gas to the maximum extent; meanwhile, a nitrogen purging system is arranged for purging residual gas of the hard-connected gas-phase unloading arm; and an emptying system is arranged to intensively collect and diffuse residual gas, so that no explosive mixed gas is remained in the operating environment. The system can fully utilize the pressure of the residual gas in the LNG tank car to recover the BOG residual gas, and reduces the influence on the environment while saving energy and reducing consumption.
Description
Technical Field
The utility model belongs to the field of LNG receiving stations, and particularly relates to a tank car residual air recovery system for an LNG receiving station.
Background
Natural gas is a clean energy, and the greenhouse gases generated after combustion only comprise 1/2 of the greenhouse gases generated after coal combustion and 2/3 of the greenhouse gases generated after petroleum combustion, so that the pollution to the environment is far less than that of the petroleum and the coal. Therefore, the natural gas is accelerated to develop and reasonably utilized, the atmospheric environment can be effectively improved, and the emission reduction target can be promoted to be realized. Furthermore, natural gas energy has attracted attention from all countries around the world due to its excellent characteristics, and thus has become a new favorite in the energy market.
In recent years, the gap of energy resources in China is continuously increased, and natural gas resources are rapidly becoming alternative energy resources of petroleum energy, so that the construction of LNG receiving terminals is greatly promoted in China, LNG receiving stations are developed like bamboo shoots in spring after rain, and large and medium-sized LNG receiving stations are continuously increased.
There are three main transportation modes of LNG or natural gas in an LNG receiving station: road tanker transport, long-distance pipeline transport and ship transport. The ship transportation is suitable for areas which are long in transportation distance and not suitable for building transportation pipelines. The transportation investment cost of the long-distance pipeline is high. Considering that natural gas resources are generally far away from the consumption market, the investment for building a remote gas pipeline is very large, the transportation mobility of the road tanker is strong, and the investment cost is low compared with pipeline transportation, so that the transportation of the road tanker is suitable for desert or inland areas. Meanwhile, the LNG has the characteristics of convenience in transportation and large gas-liquid ratio, so that the demand of gaseous natural gas can be met.
The highway tank wagon is mainly used for transporting LNG to a storage station, a distribution station, a gasification station and the like through a highway after the tank wagon is filled with the LNG in an LNG receiving station. At present, BOG residual gas in an LNG tank car mainly has two treatment modes, wherein one treatment mode is that a tank car driver usually adopts irregular operations such as a manual pressure relief mode and the like, and partial BOG in the tank car is released on the spot in an open area so as to reduce the pressure in the tank car; the other treatment mode is to add equipment such as a gasifier, a buffer tank, a booster pump and a compressor, connect the tank wagon with a recovery pipeline through a metal hose, and recover the BOG residual gas in the LNG tank wagon. The conventional LNG tank car residual gas treatment described above has the following disadvantages: (1) a large amount of BOG gas is directly diffused into the atmosphere, so that resource waste is caused, and combustible gas is discharged into the air, so that potential explosion danger is caused; (2) methane (CH) as the main component in BOG4) The BOG is a gas with strong greenhouse effect, and a large amount of BOG gas is directly diffused, so that the environment is greatly influenced; (3) a flexible connection mode is adopted, so that certain potential safety hazards exist; (4) the increased recovery equipment is more, the operation is complex, and the investment cost is high.
Therefore, the tank car residual gas recovery system for the LNG receiving station is developed to recover the BOG residual gas in the tank car, eliminate potential safety hazards and reduce environmental pollution, and has very important significance.
SUMMERY OF THE UTILITY MODEL
Aiming at the defects in the prior art, the utility model provides a tank car residual gas recovery system for an LNG receiving station based on the principles of simplicity, practicability, scientific specification, safety, high efficiency, environmental friendliness, economy and applicability.
The utility model is realized by the following technical scheme:
the utility model provides a tank car residual gas recovery system for an LNG receiving station, which comprises: the system comprises an unloading system, a pressure control and metering system, a nitrogen purging system and an emptying system; when residual gas is recovered, one end of the unloading system is connected with a gas phase port of the LNG tank wagon, the other end of the unloading system is connected with the pressure control and metering system, one end of the pressure control and metering system is connected with the unloading system, and the other end of the pressure control and metering system is connected with a BOG compressor in the LNG receiving station; after the residual gas is recovered, the nitrogen purging system (through a quick coupler) is connected with the unloading system, the pressure control and metering system and the emptying system are sequentially connected, and the tail end of the emptying system is communicated with the atmosphere.
Preferably, in the tank wagon residual gas recovery system for the LNG receiving station, the unloading system is a hard-connection gas-phase unloading arm, one end of the hard-connection gas-phase unloading arm is connected with a gas-phase port of the LNG tank wagon, and the other end of the hard-connection gas-phase unloading arm is connected with the pressure control and metering system.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, the pressure control and metering system includes a residual gas recovery main pipe and a plurality of paths of residual gas recovery branch pipes, each path of residual gas recovery branch pipe is connected in parallel, one end of each residual gas recovery branch pipe is connected with the hard-connected gas phase unloading arm, and the other end of each residual gas recovery branch pipe is connected with the residual gas recovery main pipe; one end of the residual gas recovery header pipe is connected with the residual gas recovery branch pipe, and the other end of the residual gas recovery header pipe is connected with a BOG compressor in the LNG receiving station.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, each residual gas recovery branch pipe is sequentially provided with an on-site pressure gauge, a residual gas pressure control valve, a remote pressure gauge, a flow meter and a residual gas recovery check valve; and/or an automatic shut-off valve is arranged on the residual gas recovery main pipe.
Wherein, the local pressure gauge is used for monitoring the pressure of the residual air in the tank car; the residual gas pressure control valve is used for automatically adjusting the pressure of the residual gas recovery system and stabilizing the pressure of the system; the remote transmission pressure gauge is used for monitoring the pressure after pressure regulation and sending a signal to a DCS (distributed control system); the flow meter is used for metering the flow of BOG gas recovered from the tank wagon; the residual gas recovery check valve is used for preventing the operation of other branch pipes from being influenced by the BOG gas back-flowing caused by different pressures in the LNG tank car; the automatic cut-off valve is used for interlocking and cutting off the residual gas recovery system when the pressure is over-pressure/under-pressure.
Preferably, in the tank car residual air recovery system for an LNG receiving station, the residual air pressure control valve is a self-operated pressure regulating valve; and/or the remote pressure gauge is a remote pressure transmitter with an alarm function; and/or the flowmeter is an ultrasonic flowmeter with the functions of temperature pressure compensation and flow accumulation; and/or the residual air recovery check valve is a swing check valve; and/or the automatic cut-off valve is a pneumatic switch valve.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, the nitrogen purging system includes a nitrogen purging header pipe and a plurality of nitrogen purging branch pipes, each nitrogen purging branch pipe is connected in parallel, one end of the nitrogen purging header pipe is connected with a nitrogen pipe network of the LNG receiving station, and the other end of the nitrogen purging header pipe is connected with each nitrogen purging branch pipe.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, the nitrogen purge header pipe is sequentially provided with a nitrogen pressure control valve and an on-site pressure gauge; all set gradually nitrogen gas on each way nitrogen gas sweeps branch pipe and sweep check valve, manometer and ready-packaged joint on the spot, after the residual gas is retrieved and is accomplished, the nitrogen gas sweeps the system pass through the ready-packaged joint with the system connection of unloading.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, the nitrogen pressure control valve is a self-operated pressure regulating valve; and/or the nitrogen purging check valve is a swing check valve.
Preferably, among the above-mentioned tank wagon waste gas recovery system for LNG receiving station, unloading system includes unloading house steward and multichannel unloading branch pipe, unloading branch pipe one end is retrieved the branch connection with the waste gas, the other end and is connected with unloading house steward, the unloading branch pipe sets up before the manometer on the spot of corresponding waste gas recovery branch pipe with the tie point of waste gas recovery branch pipe, and the waste gas recovery branch pipe and the unloading branch pipe of tie point department low reaches all are equipped with the hand valve, and the end of unloading house steward is linked together with the atmosphere. When the residual air is recovered, the hand valve of the emptying branch pipe is closed, and the hand valve of the corresponding residual air recovery branch pipe is opened; when the nitrogen purging is empty, the hand valve of the residual gas recovery branch pipe is closed, and the hand valve of the corresponding emptying branch pipe is opened.
Preferably, in the tank car residual gas recovery system for the LNG receiving station, a fire arrestor is arranged at the tail end of the emptying main pipe. The flame arrester is an explosion-proof flame arrester.
In order to utilize the pressure of the residual gas to the maximum extent and ensure that the LNG tank wagon has certain residual pressure, the utility model controls the operating pressure of the system to be about 0.2MPag when the residual gas recovery system normally operates. After the LNG tank wagon gas phase mouth and residual gas recovery unit are through the intercommunication of hard connection gaseous phase unloading arm, the residual gas in the LNG tank wagon gets into BOG house steward after residual gas pressure control valve throttle decompression under the drive of pressure differential. The pressure in the LNG tank car is continuously reduced along with the continuous recovery of the residual gas in the LNG tank car, and when the pressure reaches the set value of the residual gas pressure control valve, the residual gas recovery operation is automatically stopped. When the residual gas pressure control valve fails or breaks down, the remote transmission pressure gauge displays and gives an alarm on line pressure, sends a signal to the DCS, and simultaneously closes the automatic cut-off valve on the residual gas recovery main pipe in an interlocking manner. After the residual gas recovery operation is completed, the hard connection gas phase unloading arm is connected with the quick coupler on the nitrogen purging pipe branch pipe, the nitrogen from the nitrogen pipe network of the LNG receiving station is depressurized from 0.6MPag to 0.3MPag through the nitrogen pressure control valve, and then the residual gas in the hard connection gas phase unloading arm is purged and diffused, so that the residual explosive-free mixed gas in the operation environment is ensured.
In the present invention, "multiple" means two or more than two unless otherwise specified.
The technical scheme of the utility model has the following advantages:
the tank car residual gas recovery system for the LNG receiving station adopts a hard connection mode to connect a tank car gas phase port with a recovery pipeline system, controls the pressure of the system in an automatic pressure regulation mode, controls the pressure of the LNG tank car after residual gas recovery to be about 0.2MPag, automatically stops residual gas recovery when the pressure reaches a set value, triggers an alarm when overpressure occurs, and cuts off the recovery system by a parallel lock so as to ensure that BOG residual gas is recovered to the maximum extent while certain residual pressure of the LNG tank car is ensured; meanwhile, a nitrogen purging system is arranged for purging residual gas of the hard-connected gas-phase unloading arm; and an emptying system is arranged to intensively collect and diffuse residual gas so as to ensure that no explosive mixed gas remains in the operating environment. The tank car residual air recovery system has the following advantages:
(1) the pressure of residual gas in the LNG tank car can be fully utilized, pressurization equipment such as a compressor and the like is not needed, energy is saved, consumption is reduced, and the cost is low;
(2) BOG in the LNG tank car can be recovered to the maximum extent, the BOG can be recycled after being processed by a BOG processing system in the receiving station, and the economic benefit is remarkable;
(3) the device can be simultaneously used for recovering residual gas of a plurality of LNG tank cars, so that the investment cost is saved;
(4) direct emission of a large amount of BOG gas is reduced, and the influence on the environment is reduced;
(5) the operation is convenient, the preparation work before the liquid filling is simplified, and the filling period of the LNG tank car is shortened.
(6) The method can be popularized and applied to the field of residual gas recovery of the medium with the similar properties to LNG, and has strong applicability and wide application range.
Drawings
In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the present disclosure taken in conjunction with the accompanying drawings, in which:
fig. 1 is a schematic structural diagram of a tank car residual gas recovery system for an LNG receiving station according to an embodiment of the present invention;
the system comprises a unloading system, a pressure control and metering system, a nitrogen purging system and a venting system, wherein the unloading system is 1, the pressure control and metering system is 2, and the venting system is 4;
1-first hard-connected gas-phase unloading arm, 1-2-second hard-connected gas-phase unloading arm, 1-3-third hard-connected gas-phase unloading arm, 1-4-fourth hard-connected gas-phase unloading arm, 2-1-residual gas recovery header pipe, 2-first residual gas recovery branch pipe, 2-3-second residual gas recovery branch pipe, 2-4-third residual gas recovery branch pipe, 2-5-fourth residual gas recovery branch pipe, 3-1-nitrogen purging header pipe, 3-2-first nitrogen purging branch pipe, 3-second nitrogen purging branch pipe, 3-4-third nitrogen purging branch pipe, 3-fast-assembly 5-fourth nitrogen purging branch pipe, 3-6-first joint, 3-7-second joint, 3-8-third joint, 3-9-fourth joint, 4-1-a vent main, 4-2-a first vent branch, 4-3-a second vent branch, 4-a third vent branch, 4-5-a fourth vent branch, and 4-6-a flame arrester;
PG 001-first in-situ pressure gauge, PG 002-second in-situ pressure gauge, PG 003-third in-situ pressure gauge, PG 004-fourth in-situ pressure gauge, PG 005-fifth in-situ pressure gauge, PG 006-sixth in-situ pressure gauge, PG 007-seventh in-situ pressure gauge, PG 008-eighth in-situ pressure gauge, PG 009-ninth in-situ pressure gauge, PCV 001-first residual gas pressure control valve, PCV 002-second residual gas pressure control valve, PCV 003-third residual gas pressure control valve, PCV 004-fourth residual gas pressure control valve, PCV 005-nitrogen pressure control valve, CH-001-first residual gas recovery check valve, CH-002-second residual gas recovery check valve, CH-003-third residual gas recovery check valve, CH-004-fourth residual gas recovery check valve, CH-005-first nitrogen purge check valve, CH-006-second nitrogen purge check valve, CH-007-third nitrogen purge check valve, CH-008-fourth nitrogen purging check valve, XV 001-automatic cut-off valve, PIA 001-first remote transmission pressure gauge, PIA 002-second remote transmission pressure gauge, PIA 003-third remote transmission pressure gauge, PIA 004-fourth remote transmission pressure gauge, FIT 001-first flowmeter, FIT 002-second flowmeter, FIT 003-third flowmeter and FIT 004-fourth flowmeter.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "provided", "connected", and the like are to be construed broadly, such as "connected", which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Examples
As shown in fig. 1, the tank car residual gas recovery system for an LNG receiving station in this embodiment can simultaneously recover residual gas from 4 LNG tank cars, and the system includes: the system comprises an unloading system 1, a pressure control and metering system 2, a nitrogen purging system 3 and an emptying system 4; when residual gas is recovered, one end of the unloading system 1 is connected with a gas phase port of the LNG tank wagon, the other end of the unloading system is connected with the pressure control and metering system 2, one end of the pressure control and metering system 2 is connected with the unloading system 1, and the other end of the pressure control and metering system is connected with a BOG compressor in the LNG receiving station; after the residual gas is recovered, the nitrogen purging system 3 is connected with the unloading system 1, the pressure control and metering system 2 and the emptying system 4 are sequentially connected, and the tail end of the emptying system 4 is communicated with the atmosphere.
The unloading system 1 comprises a first hard-connection gas-phase unloading arm 1-1, a second hard-connection gas-phase unloading arm 1-2, a third hard-connection gas-phase unloading arm 1-3 and a fourth hard-connection gas-phase unloading arm 1-4, one end of the first hard-connection gas-phase unloading arm 1-1 is connected with a gas phase port of a 1# LNG tank wagon, the other end of the first hard-connection gas-phase unloading arm is connected with a pressure control and metering system 2, one ends of the other hard-connection gas-phase unloading arms 1-2-1-4 are connected with the gas phase port of a corresponding 2# to 4# tank wagon, and the other ends of the other hard-connection gas-phase unloading arms are connected with the pressure control and metering system 2.
Wherein the pressure control and metering system 2 comprises a residual gas recovery main pipe 2-1, a first residual gas recovery branch pipe 2-2, a second residual gas recovery branch pipe 2-3, a third residual gas recovery branch pipe 2-4 and a fourth residual gas recovery branch pipe 2-5, the residual gas recovery branch pipes 2-5 are arranged in parallel and can run simultaneously and are standby each other, one end of the first residual gas recovery branch pipe 2-2 is connected with a first hard connection gas phase unloading arm 1-1, the other end is connected with the residual gas recovery main pipe 2-1, one end of the residual gas recovery branch pipe 2-3-2-5 is connected with the corresponding hard connection gas phase unloading arm 1-2-1-4, the other end is connected with the residual gas recovery main pipe 2-1, one end of the residual gas recovery main pipe 2-1 is connected with the residual gas recovery branch pipes 2-5, and the residual gas recovery branch pipes 2-1 are connected with the residual gas recovery branch pipes 2-1, The other end is connected with a BOG compressor in the LNG receiving station. The first residual gas recovery branch pipe 2-2 is sequentially provided with a first local pressure gauge PG001, a first residual gas pressure control valve PCV001, a first remote pressure gauge PIA001, a first flow meter FIT001 and a first residual gas recovery check valve CH-001. The other paths of residual gas recovery branch pipes 2-3-2-5 are also sequentially provided with corresponding on-site pressure gauges PG 002-PG 004, residual gas pressure control valves PCV 002-PCV 004, remote transmission pressure gauges PIA 002-PIA 004, flow meters FIT 002-FIT 004 and residual gas recovery check valves CH-002-CH-004. An automatic cut-off valve XV001 is arranged on the residual gas recovery main pipe 2-1. All the residual air pressure control valves in the embodiment are self-operated pressure regulating valves; each remote transmission pressure gauge is a remote transmission pressure transmitter with an alarm function; each flow meter is an ultrasonic flow meter with the functions of temperature pressure compensation and flow accumulation; each residual air recovery check valve is a swing check valve; the automatic cut-off valve XV001 is a pneumatic switch valve.
And local pressure gauges on the residual gas recovery branch pipes are used for monitoring the residual gas pressure in the tank car. The residual gas pressure control valve is used for automatically adjusting the pressure of the residual gas recovery system and stabilizing the pressure of the system. The remote transmission pressure gauge is used for monitoring the pressure after pressure regulation and sending signals to the DCS distributed control system. The flow meter is used for metering the flow of BOG gas recovered from the tank car. When a plurality of LNG tank cars simultaneously carry out the residual gas recovery, the residual gas recovery check valve is used for preventing the operation of other branch pipes from being influenced by the BOG gas reverse channeling caused by different pressures in the LNG tank cars. The automatic cut-off valve is used for interlocking and cutting off the residual gas recovery system when the pressure is over-pressure/under-pressure.
The nitrogen purging system 3 comprises a nitrogen purging header pipe 3-1, a first nitrogen purging branch pipe 3-2, a second nitrogen purging branch pipe 3-3, a third nitrogen purging branch pipe 3-4 and a fourth nitrogen purging branch pipe 3-5, the nitrogen purging branch pipes are connected in parallel, one end of the nitrogen purging header pipe 3-1 is connected with a nitrogen pipe network of the LNG receiving station, and the other end of the nitrogen purging header pipe 3-1 is connected with the nitrogen purging branch pipes 3-2-3-5. The nitrogen purging header pipe 3-1 is sequentially provided with a nitrogen pressure control valve PCV005 and a fifth in-situ pressure gauge PG 005. The first nitrogen purging branch pipe 3-2 is sequentially provided with a first nitrogen purging check valve CH-005, a sixth on-site pressure gauge PG006 and a first quick coupler 3-6. The other nitrogen purging branch pipes 3-5 are also sequentially provided with corresponding nitrogen purging check valves CH-006-CH-008, local pressure gauges PG 007-PG 009 and quick connectors 3-7-3-9. After the residual gas is recovered, the nitrogen purging system 3 is connected with the first hard-connected gas-phase unloading arm 1-1 through the first quick connectors 3-6 and connected with the corresponding hard-connected gas-phase unloading arms 1-2-1-4 through the other quick connectors 3-7-3-9. The nitrogen pressure control valve PCV005 in the present embodiment is a self-operated pressure regulating valve; each nitrogen purging check valve is a swing check valve.
The emptying system 4 comprises an emptying header 4-1, a first emptying branch pipe 4-2, a second emptying branch pipe 4-3, a third emptying branch pipe 4-4 and a fourth emptying branch pipe 4-5. One end of the first emptying branch pipe 4-2 is connected with the first residual gas recovery branch pipe 2-2, the other end is connected with the emptying header pipe 4-1, the connection point of the first emptying branch pipe 4-2 and the first residual gas recovery branch pipe 2-2 is arranged in front of a first on-site pressure gauge PG001, the first residual gas recovery branch pipe 2-2 and the first emptying branch pipe 4-2 at the downstream of the connection point are both provided with hand valves (omitted in the drawing), one end of each of the other emptying branch pipes 4-3-4-5 is connected with the corresponding residual gas recovery branch pipe 2-3-2-5, the other end is connected with the emptying header pipe 4-1, the connection point of each of the other emptying branch pipes 4-3-4-5 and the corresponding residual gas recovery branch pipe 2-3-2-5 is also arranged in front of the corresponding on-site pressure gauge PG 002-004, the other emptying branch pipes 4-3-4-5 at the downstream of the connecting point and the corresponding residual air recovery branch pipes 2-3-2-5 are also provided with hand valves (omitted in the drawing), and the tail end of the emptying header pipe 4-1 is communicated with the atmosphere. The tail end of the emptying main pipe 4-1 is provided with a flame arrester 4-6, and the flame arrester 4-6 in the embodiment is an explosion-proof flame arrester.
The operation principle is as follows:
in order to utilize the pressure of the residual gas to the maximum extent and ensure that the LNG tank wagon has a certain residual pressure, the operation pressure of the system is controlled to be about 0.2MPag when the residual gas recovery system operates normally in the embodiment. The 1# LNG tank car is taken as an example for explanation. When the gas phase port of the No. 1 LNG tank car is communicated with the first hard connection gas phase unloading arm 1-1 of the tank car residual gas recovery system and residual gas is recovered, a hand valve in front of a first local pressure gauge PG001 on the first residual gas recovery branch pipe 2-2 is opened, a hand valve on the first emptying branch pipe 4-2 is closed, and residual gas in the No. 1 LNG tank car is throttled and depressurized by a first residual gas pressure control valve PCV001 under the driving of pressure difference and then enters a residual gas recovery main pipe 2-1. With the continuous recovery of the residual gas in the No. 1 LNG tank car, the pressure in the tank car is continuously reduced, and when the pressure in the tank car reaches the set value (0.2MPag) of the first residual gas pressure control valve PCV001, the residual gas recovery operation is automatically stopped. When the first residual air pressure control valve PCV001 fails or breaks down, the first remote transmission pressure gauge PIA001 gives an alarm (the low alarm value is 0.15MPag, and the high alarm value is 0.35MPag), sends a signal to the DCS, and interlocks to close the automatic cutoff valve XV 001.
The ultrasonic flow meters with temperature pressure compensation and flow accumulation functions are arranged on the residual gas recovery branch pipes, so that the recovered BOG flow of each tank car and the accumulated total BOG recovery amount of the whole residual gas recovery device can be measured in real time.
After the residual gas recovery operation is finished, a first hard-connection gas phase unloading arm 1-1 is connected with a first nitrogen purging branch pipe 3-2 through a first quick-assembly joint 3-6, a hand valve (omitted in the drawing and the same below) in front of a first on-site pressure gauge PG001 on the first residual gas recovery branch pipe 2-2 is closed, a hand valve (omitted in the drawing and the same below) on a first emptying branch pipe 4-2 is opened, the rest hard-connection gas phase unloading arms 1-2-1-4 are also connected with the corresponding nitrogen purging branch pipes 3-5 through corresponding quick-assembly joints 3-7-3-9, the hand valves in front of on-site pressure gauges 002-004 on the rest of residual gas recovery branch pipes 2-3-2-5 are closed, the hand valves on the rest of emptying branch pipes 4-3-4-5 are opened, after the nitrogen pressure of nitrogen from a nitrogen pipe network of an LNG receiving station is reduced from 0.6MPag to 0.3MPag through a nitrogen pressure control valve PCV005, residual gas in each hard-connected gas phase unloading arm 1-4 is purged, the residual gas is intensively converged to an emptying main pipe 4-1 through each path of emptying branch pipes 4-2-4-5, and is diffused to a safe area after flowing through an explosion-resistant flame retardant flame arrester 4-6 at the tail end of the emptying main pipe 4-1, so that no explosive mixed gas is remained in the operating environment.
In the tank car residual gas recovery system for the LNG receiving station in the embodiment, each path of residual gas recovery branch pipe is arranged in parallel and is mutually standby, and the residual gas recovery system is applied to residual gas recovery of a plurality of LNG tank cars, so that the residual gas recovery time is saved, and the operation flexibility and stability of the pressure of the residual gas recovery system are improved; in addition, the BOG residual gas can be recovered by fully utilizing the pressure of the residual gas, so that the energy is saved, the consumption is reduced, the influence on the environment is reduced, and the requirements of resource conservation, environmental friendliness and remarkable benefit are met.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the utility model may be made without departing from the spirit or scope of the utility model.
Claims (10)
1. A tank car residual gas recovery system for an LNG receiving station, comprising: the system comprises an unloading system (1), a pressure control and metering system (2), a nitrogen purging system (3) and an emptying system (4); when residual gas is recovered, one end of the unloading system (1) is connected with a gas phase port of the LNG tank car, the other end of the unloading system is connected with the pressure control and metering system (2), one end of the pressure control and metering system (2) is connected with the unloading system (1), and the other end of the pressure control and metering system is connected with a BOG compressor in the LNG receiving station; after the residual gas is recovered, the nitrogen purging system (3) is connected with the unloading system (1), the pressure control and metering system (2) is sequentially connected with the emptying system (4), and the tail end of the emptying system (4) is communicated with the atmosphere.
2. Tank wagon residual gas recovery system for LNG receiving stations according to claim 1, characterized in that the unloading system (1) is a hard-connected gas phase unloading arm, one end of which is connected to the gas phase port of the LNG tank wagon and the other end is connected to the pressure control and metering system (2).
3. The tank car residual gas recovery system for the LNG receiving station as claimed in claim 2, wherein the pressure control and metering system (2) comprises a residual gas recovery header pipe (2-1) and a plurality of residual gas recovery branch pipes, each residual gas recovery branch pipe is arranged in parallel with each other, one end of each residual gas recovery branch pipe is connected with the hard-connection gas phase unloading arm, the other end of each residual gas recovery branch pipe is connected with the residual gas recovery header pipe (2-1), one end of each residual gas recovery header pipe (2-1) is connected with each residual gas recovery branch pipe, and the other end of each residual gas recovery header pipe is connected with a BOG compressor in the LNG receiving station.
4. The tank car residual gas recovery system for an LNG receiving station according to claim 3, wherein each residual gas recovery branch pipe is provided with an on-site pressure gauge, a residual gas pressure control valve, a remote pressure gauge, a flow meter and a residual gas recovery check valve in sequence; and/or an automatic cut-off valve is arranged on the residual gas recovery main pipe (2-1).
5. The tank car residual gas recovery system for an LNG receiving station of claim 4, wherein the residual gas pressure control valve is a self-operated pressure regulating valve; and/or the remote pressure gauge is a remote pressure transmitter with an alarm function; and/or the flowmeter is an ultrasonic flowmeter with the functions of temperature pressure compensation and flow accumulation; and/or the residual air recovery check valve is a swing check valve; and/or the automatic cut-off valve is a pneumatic switch valve.
6. The tank car residual gas recovery system for the LNG receiving station as claimed in any one of claims 1 to 5, wherein the nitrogen purging system (3) comprises a nitrogen purging header pipe (3-1) and a plurality of nitrogen purging branch pipes, the nitrogen purging branch pipes are arranged in parallel, one end of the nitrogen purging header pipe (3-1) is connected with a nitrogen pipe network of the LNG receiving station, and the other end of the nitrogen purging header pipe is connected with the nitrogen purging branch pipes.
7. The tank car residual gas recovery system for the LNG receiving station as claimed in claim 6, wherein the nitrogen purge header pipe (3-1) is provided with a nitrogen pressure control valve and an on-site pressure gauge in sequence; all set gradually nitrogen gas on each way nitrogen gas sweeps branch pipe and sweep check valve, manometer and ready-packaged joint on the spot, and after the residual gas was retrieved and is accomplished, nitrogen gas sweeps system (3) through the ready-packaged joint with unloading system (1) is connected.
8. The tank car residual gas recovery system for an LNG receiving station according to claim 7, wherein the nitrogen pressure control valve is a self-operated pressure regulating valve; and/or the nitrogen purging check valve is a swing check valve.
9. The tank car residual gas recovery system for an LNG receiving station according to any one of claims 1 to 5, characterized in that the emptying system (4) comprises an emptying header (4-1) and a plurality of emptying branch pipes, one end of each emptying branch pipe is connected with the residual gas recovery branch pipe, the other end of each emptying branch pipe is connected with the emptying header (4-1), the connection point of each emptying branch pipe and the residual gas recovery branch pipe is arranged in front of the on-site pressure gauge of the corresponding residual gas recovery branch pipe, and the tail end of the emptying header (4-1) is communicated with the atmosphere.
10. The tank car residual gas recovery system for an LNG receiving station according to claim 9, characterized in that the end of the emptying main (4-1) is provided with a flame arrester (4-6), the flame arrester (4-6) being of the explosion-proof type.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120772140.6U CN216520911U (en) | 2021-04-15 | 2021-04-15 | Tank car residual gas recovery system for LNG receiving station |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120772140.6U CN216520911U (en) | 2021-04-15 | 2021-04-15 | Tank car residual gas recovery system for LNG receiving station |
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| Publication Number | Publication Date |
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| CN216520911U true CN216520911U (en) | 2022-05-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120772140.6U Active CN216520911U (en) | 2021-04-15 | 2021-04-15 | Tank car residual gas recovery system for LNG receiving station |
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| Country | Link |
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| CN (1) | CN216520911U (en) |
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2021
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