CN215862922U

CN215862922U - Regional modular gas leakage monitoring, prevention and control system of LNG (liquefied natural gas) gasification device

Info

Publication number: CN215862922U
Application number: CN202122202008.4U
Authority: CN
Inventors: 李永冲; 席彬杰; 胡敏; 年继平; 朱章平; 李增辉
Original assignee: Shaanxi Liquefied Natural Gas Invest & Dev Co ltd
Current assignee: Shaanxi Liquefied Natural Gas Invest & Dev Co ltd
Priority date: 2021-09-10
Filing date: 2021-09-10
Publication date: 2022-02-18
Anticipated expiration: 2031-09-10

Abstract

The utility model discloses a regional modular gas leakage monitoring, prevention and control system of an LNG (liquefied natural gas) gasification device, which comprises an LNG buffer tank, wherein the LNG buffer tank is communicated with an LNG booster pump, the LNG booster pump is communicated with an SCV (sub-grid-voltage) submerged combustion type gasifier, and a pipeline between the LNG booster pump and the SCV submerged combustion type gasifier is provided with a stop valve; the SCV submerged combustion type gasifier is connected with the blower and communicated with the natural gas pipe network; a fuel gas leakage monitoring module is arranged around an area formed by the LNG buffer tank, the LNG booster pump, the SCV submerged combustion type gasifier and the blower; the gas leakage monitoring module and the stop valve are connected with a central control room, and the central control room is connected with a ventilation module. Through high-efficient, accurate monitoring in the region, the effectual compulsory shut down of power take off equipment and the auto-lock protection of core equipment after solving natural gas leakage and taking place reach the regional detection of combustible gas leakage and the safe urgent prevention and control of system equipment facility, realize the essential safety of unit equipment facility operation and the prevention of secondary disaster.

Description

Regional modular gas leakage monitoring, prevention and control system of LNG (liquefied natural gas) gasification device

Technical Field

The utility model belongs to the technical field of gas leakage, and relates to a regional modular gas leakage monitoring, prevention and control system of an LNG gasification device.

Background

With the continuous expansion of the natural gas application market, gas utilization safety also becomes a key concern in production and life. In recent years, safety production accidents in the natural gas application process are frequent, and according to incomplete statistics, 88 people die and 496 people are injured due to gas safety accidents 539 accumulated by factors such as improper operation, damaged pipe fittings and valves, improper construction and the like in 2020. In order to ensure the environmental safety of natural gas use places and prevent the natural gas from continuously leaking and causing flash explosion and fire risks, the petrochemical enterprise combustible gas and toxic and harmful gas detection and alarm design specification (GB50493-2009) specifies that when the concentration of combustible gas in leaked gas reaches an alarm set value in the areas of production facilities, storage facilities and transportation facilities for producing or using combustible gas and toxic and harmful gas, a combustible gas detector is required to be arranged so as to ensure that operators can make a judgment timely and accurately when natural gas leakage occurs in the use areas. The traditional gas leakage monitoring is set as a point-type gas leakage detector, and explosion, fire and other more extensive accidents and secondary disasters can be caused by the limitation of artificial thinking or the emergency response time in the production process.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a regional modular gas leakage monitoring, prevention and control system for an LNG (liquefied natural gas) gasification device, which solves the problems that more extensive accidents such as deflagration, fire and the like and secondary disasters are possibly caused by artificial thinking limitation or emergency response timeliness in the prior art.

The technical scheme adopted by the utility model is that the regional modular gas leakage monitoring, prevention and control system of the LNG gasification device comprises an LNG buffer tank, wherein the LNG buffer tank is communicated with an LNG booster pump, the LNG booster pump is communicated with an SCV submerged combustion type gasifier, and a cut-off valve is arranged on a pipeline between the LNG booster pump and the SCV submerged combustion type gasifier; the SCV submerged combustion type gasifier is connected with the blower and communicated with the natural gas pipe network; a fuel gas leakage monitoring module is arranged around an area formed by the LNG buffer tank, the LNG booster pump, the SCV submerged combustion type gasifier and the blower; the gas leakage monitoring module and the cut-off valve are connected with an emergency prevention and control logic control module of a central control room, and a fresh air compressor module is arranged above the central control room; wherein, the gas leakage monitoring module mainly used monitors LNG buffer tank, LNG booster pump, SCV submerged combustion formula vaporizer, and the emergent prevention and control logic control module of well accuse room is used for controlling the closing of trip valve, LNG booster pump and SCV submerged combustion formula vaporizer according to the conveying data control of gas leakage monitoring module, and fresh air compressor module is used for cooling down the supervisory equipment of well accuse room and takes a breath.

The utility model is also characterized in that:

the gas leakage monitoring module comprises a plurality of gas leakage detectors arranged around the LNG buffer tank, the LNG booster pump and the SCV submerged combustion type gasifier, and the gas leakage detectors are connected with an emergency prevention and control logic control module of the central control room.

The gas leakage detector consists of a transmitter and a receiver, the gas leakage detector is connected with an emergency prevention and control logic control module of a central control room through an alarm repeater, and the transmitter and the receiver are installed and pulled apart for a certain distance according to an axis to form a monitoring area.

The shut-off valve 985SDV019 is a carburetor inlet shut-off valve.

The gas leakage detector is a four-set correlation type combustible gas detector of AT981-1a/b, AT981-2a/b, AT981-3a/b and AT981-4 a/b.

The emergency prevention and control logic control module comprises an FGS alarm system, an SIS interlocking turn-off system and a central control room DCS operation control system.

The utility model has controllable area coverage and higher automation degree integrity, and effectively solves the forced shutdown of the power output equipment and the self-locking protection of the core equipment after the natural gas leakage occurs through high-efficiency and accurate in-area monitoring, thereby reducing the accident occurrence probability, realizing the intrinsic safety of equipment facilities, achieving the regional detection of the combustible gas leakage and the safe emergency prevention and control of system equipment facilities, and realizing the intrinsic safety of the operation of unit equipment facilities and the prevention of secondary disasters.

Drawings

FIG. 1 is a schematic view of a gasification unit area modular gas leakage monitoring, prevention and control system;

in the figure, 1, an LNG buffer tank, 2, an LNG booster pump, 3, an SCV submerged combustion type gasifier, 4, a blower, 5, a fresh air compressor module, 6, a gas leakage monitoring module, 7, a central control room, 8, an emergency prevention and control logic control module and 9, a cut-off valve.

Detailed Description

The present invention will be described in detail with reference to fig. 1.

The utility model discloses a regional modular gas leakage monitoring, prevention and control system of an LNG (liquefied natural gas) gasification device, which comprises an LNG buffer tank 1, wherein the LNG buffer tank 1 is communicated with an LNG booster pump 2, the LNG booster pump 2 is communicated with an SCV (submerged combustion type) gasifier 3, and a pipeline between the LNG booster pump 2 and the SCV submerged combustion type gasifier 3 is provided with a stop valve 9; the SCV submerged combustion type gasifier 3 is connected with the blower 4, and the SCV submerged combustion type gasifier 3 is communicated with a natural gas pipe network; a fuel gas leakage monitoring module 6 is arranged around an area formed by the LNG buffer tank 1, the LNG booster pump 2, the SCV submerged combustion type gasifier 3 and the blower 4; the gas leakage monitoring module 6 and the shut-off valve 9 are connected with an emergency prevention and control logic control module 8 of the central control room 7, and a fresh air compressor module 5 is arranged above the central control room 7. Wherein, gas leakage monitoring module 6 comprises 4 gas leakage detectors.

After LNG from the storage area outside the country gets into LNG buffer tank 1, then LNG gets into LNG booster pump 2 from LNG buffer tank 1 under the pressure differential effect and carries out the pressure boost, and the LNG after the pressure boost gets into SCV submerged combustion formula vaporizer 3 and carries out the gasification that heats for the natural gas returns to defeated outside pipe network. In the actual operation, it is found that the natural gas leakage is caused by three parts, i.e., the LNG surge tank 1, the LNG booster pump 2, and the SCV submerged combustion vaporizer 3, and a region formed by these three parts is referred to as a vaporizer unit in the present invention.

The blower 4 primarily provides air for combustion of the SCV submerged combustion gasifier 3, and the blower motor 4 is a non-explosion-proof device, creating a fire explosion risk with large amounts of natural gas. A large amount of leaked fuel gas can be sucked into a compressor motor of the fresh air compressor system 5, the compressor motor is non-explosion-proof equipment and can form fire explosion risks with the leaked large amount of natural gas, and the operation of the whole gasification device unit is monitored and operated in a central control room by a natural gas application system, so that the fresh air compressor module 5 is added, the fresh air compressor module 5 is a fresh air system and is arranged at the 10-meter position on the east side of the gasification device unit area, and the temperature of the fresh air compressor module is mainly reduced by monitoring equipment of the central control room 7.

The emergency prevention and control logic control module 8 arranged in the central control room 7 comprises an FGS alarm system, an SIS interlocking turn-off system and a central control room DCS operation control system. When the natural gas leakage occurs in the gasification device unit, when the gas leakage detector detects that the concentration of the combustible gas reaches a high alarm value, the FGS alarm system sends an alarm signal to be fed back to the SIS interlocking turn-off system, so that the SCV submerged combustion type gasifier 3 can be stopped emergently, and the device can start the LNG booster pump 2 to be stopped in an interlocking manner, thereby realizing the whole logic process of the whole safe stop of the gasification device unit.

The motors of the existing air blower and the fresh air compressor are non-explosion-proof equipment, and the air blower is arranged in the gasification device area. The fresh air compressor is close to the gasification device. The non-explosion-proof motor with the running blower and the fresh air compressor and a large amount of leaked natural gas can cause fire explosion accidents, so the system fundamentally avoids the accidents.

During the operation of the gasification device unit in the natural gas peak conservation, if the gas leakage monitoring module 6 detects that the concentration of combustible gas exceeds the standard, an alarm signal is sent, the interlocking SCV submerged combustion type gasifier 3 is stopped emergently, meanwhile, the device interlocks to start the LNG booster pump 2 to stop, and the gasification device unit is stopped safely as a whole. The specific setting logic is as follows:

c: when the gas leakage monitoring module 6 detects that the concentration of the combustible gas reaches a high alarm value, an alarm signal is sent to interlock the SCV submerged combustion gasifier 3 to stop;

c: the SCV submerged combustion type gasifier 3 is shut down, an inlet cut-off valve 9 of the interlocking SCV submerged combustion type gasifier 3 is closed, and low-temperature LNG is effectively isolated from entering the SCV submerged combustion type gasifier 3;

c: and an inlet emergency cut-off valve 9 of the SCV submerged combustion type gasifier 3 is closed, the interlocking LNG booster pump 2 is stopped, and the leakage of LNG is cut off.

The gas leakage detector selects the current advanced remote infrared light combustible gas detector in the market, the detector consists of an emitter and a receiver, and the gas detector is connected with a central control room through an alarm repeater. The transmitter and the receiver are installed and pulled apart for a certain distance according to the axis to form a monitoring area, and the combustible gas leakage area is surrounded by infrared light, so that the natural gas leakage is omnibearing, and no dead angle monitoring is realized. When the combustible gas content is detected to reach high level, the interlocking device forms self-locking protection.

The system of the utility model optimizes the software and hardware facilities of the original point type combustible gas detector by the practical application of the combustible gas detection system in the device area, and simultaneously, the logic of the fire and gas alarm system is reasonably and thoroughly set by combining the working environment of the equipment facilities. Adopting advanced technical measures to achieve regional detection of combustible gas leakage; the safety emergency prevention and control of system equipment facilities realizes the intrinsic safety of the operation of unit facilities; and (4) restraining the system in a crossing manner, and preventing secondary disasters from happening.

Claims

1. The regional modular gas leakage monitoring, preventing and controlling system of the LNG gasification device is characterized by comprising an LNG buffer tank (1), wherein the LNG buffer tank (1) is communicated with an LNG booster pump (2), the LNG booster pump (2) is communicated with an SCV submerged combustion type gasifier (3), and a cut-off valve (9) is arranged on a pipeline between the LNG booster pump (2) and the SCV submerged combustion type gasifier (3); the SCV submerged combustion type gasifier (3) is connected with a blower (4), and the SCV submerged combustion type gasifier (3) is communicated with a natural gas pipe network; a gas leakage monitoring module (6) is arranged around a region formed by the LNG buffer tank (1), the LNG booster pump (2), the SCV submerged combustion type gasifier (3) and the blower (4); the gas leakage monitoring module (6) and the shut-off valve (9) are communicated with an emergency prevention and control logic control module (8) of a central control room (7), and a fresh air compressor module (5) is arranged above the central control room (7); wherein, gas leakage monitoring module (6) mainly used monitors LNG buffer tank (1), LNG booster pump (2), SCV submerged combustion formula vaporizer (3), the emergent prevention and control logic control module (8) of well accuse room (7) are used for controlling closing of trip valve (9), LNG booster pump (2) and SCV submerged combustion formula vaporizer (3) according to the data transmission of gas leakage monitoring module (6), fresh air compressor module (5) are used for cooling down the supervisory equipment of well accuse room (7).

2. The regional modular gas leakage monitoring, prevention and control system of LNG vaporizer according to claim 1, characterized in that the gas leakage monitoring module (6) comprises several gas leakage detectors installed around the LNG buffer tank (1), LNG booster pump (2), SCV submerged combustion vaporizer (3), and the gas leakage detectors are connected with the emergency prevention and control logic control module (8) of the central control room (7).

3. The system of claim 2, wherein the gas leakage detector comprises a transmitter and a receiver, the gas leakage detector is connected to the central control room through an alarm relay, and the transmitter and the receiver are installed and separated by a certain distance along an axis to form a monitoring area.

4. The LNG vaporizer regional modular gas leakage monitoring, prevention and control system according to claim 1, characterized in that the shut-off valve (9) is a 985SDV019 vaporizer inlet shut-off valve.

5. The regional modular gas leakage monitoring, prevention and control system of an LNG gasification device as claimed in claim 2, characterized in that the gas leakage detectors are AT981-1a/b, AT981-2a/b, AT981/3a/b, AT981-4a/b four sets of correlation type combustible gas detectors.

6. The LNG gasification facility regional modular gas leakage monitoring, prevention and control system of claim 1, characterized in that the emergency prevention and control logic control module (8) comprises an FGS alarm system, an SIS interlock shutdown system and a central control room DCS operation control system.