A safety protection system and method for gas co-management

Abstract

The present invention provides a safety protection system and method for gas-phase co-management, including: an LNG storage system, the LNG storage system including at least ten tank container systems, the tank container system including an LNG tank container storing LNG; a main pipeline system, the main pipeline system including a main medium pipeline; a safety monitoring and control system, the safety monitoring and control system including a controller, a first pressure sensor and a second pressure sensor; the controller is used for receiving the pressure value data sent by the first pressure sensor and the second pressure sensor and controlling the opening and closing of the alarm. When the pressure value in a certain LNG tank container is greater than a preset value (such as 0.5 MPa), the safety protection system for gas-phase co-management prompts the staff to connect the LNG tank container to the main medium pipeline, realizing gas-phase co-management.

Description

Technical Field

[0001] The present invention relates to the field of BOG protection systems, and in particular to a safety protection system and method for gas-phase co-management. Background Art

[0002] During the storage, transportation, unloading, and filling of liquefied natural gas (LNG), it is inevitable to absorb heat from the outside world and generate boil-off gas (BOG). The generation of BOG causes the pressure in the LNG storage tank to rise rapidly. When the pressure exceeds the allowable working pressure, the safety protection device of the LNG storage tank is activated to discharge and decompress the BOG. The BOG discharged into the external air is likely to cause serious safety hazards, and in the case of multiple LNG tank containers, such as on an LNG carrier or in a yard, this problem of safety hazards is particularly serious.

[0003] Therefore, it is necessary to improve the existing technology. Summary of the Invention

[0004] The problem solved by the present invention is that when the LNG tank container is over-pressurized, directly discharging the BOG into the external space will cause serious safety hazards. The present invention provides a safety protection system and method for gas-phase co-management to solve the above problems.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0006] A safety protection system for gas-phase co-management, comprising:

[0007] An LNG storage system, the LNG storage system includes at least ten groups of tank container systems, the tank container system includes an LNG tank container storing LNG; a first male connector is connected to the BOG gas phase space inside the LNG tank container through a first connecting pipe; an alarm is provided on the LNG tank container; a first manual stop valve is installed on the first connecting pipe;

[0008] A main pipeline system, the main pipeline system includes a main medium pipeline and a plurality of first male connectors matching the first male connector, each first male connector is connected to the main medium pipeline through a second connecting hose; when the first male connector is inserted into the first male connector, the corresponding first connecting pipe and the second connecting hose are connected;

[0009] A safety monitoring and control system, the safety monitoring and control system includes a controller, a first pressure sensor, and a second pressure sensor;

[0010] The first pressure sensor is used to detect the pressure value in the BOG gas phase space of the LNG tank container; the second pressure sensor is used to detect the pressure value of BOG in the main medium pipeline;

[0011] The controller is used to receive the pressure value data sent by the first pressure sensor and the second pressure sensor and control the opening and closing of the alarm.

[0012] Preferably, a BOG reliquefaction recovery system is further included. The BOG reliquefaction recovery system includes a regenerative refrigerator, and the regenerative refrigerator includes a cryogenic heat exchanger; a second medium pipeline is connected between the inlet of the cryogenic heat exchanger and the main medium pipeline; the connection point of the second medium pipeline and the main medium pipeline is located between the first end and the second end of the main medium pipeline; a second pneumatic regulating valve is installed on the second medium pipeline, and the controller controls the opening or closing of the regenerative refrigerator and the second pneumatic regulating valve.

[0013] Preferably, a reliquefied BOG storage system is further included. The reliquefied BOG storage system includes a spray head and a liquid storage tank. The spray head is arranged in the liquid storage tank and at the top of the liquid storage tank. The spray head has an inlet extending out of the liquid storage tank; a third medium pipeline is connected between the inlet of the spray head and the outlet of the cryogenic heat exchanger.

[0014] Preferably, a natural gas power system is further included. The natural gas power system includes a combustion system and a cold energy recovery device; the combustion system is used to burn BOG to drive the gas turbine to operate; a first medium pipeline is connected between the inlet of the combustion system and the first end of the main medium pipeline; a first pneumatic regulating valve is arranged on the main medium pipeline, and the first pneumatic regulating valve is close to the first end of the main medium pipeline; the controller controls the opening or closing of the first pneumatic regulating valve;

[0015] The cold energy recovery device is a heat exchanger with multiple inlets and multiple outlets. The heat exchanger is installed in the first medium pipeline, the internal gas turbine air pipeline, the cold air system pipeline of the tank container transport ship, and the gas turbine exhaust and circulating cooling water pipeline through different inlets and outlets.

[0016] Preferably, a mast ignition system is further included. The mast ignition system includes a safety valve, a mast exhaust pipe, and an igniter. The second end of the main medium pipeline is connected to the inlet of the mast exhaust pipe, and the outlet of the mast exhaust pipe communicates with the outside; the igniter is arranged at the outlet of the mast exhaust pipe; the safety valve is arranged at the second end of the main medium pipeline; the controller controls the ignition of the igniter.

[0017] Preferably, the safety monitoring and control system further includes a third pressure sensor for detecting the pressure value in the BOG gas phase space inside the liquid storage tank;

[0018] A fourth medium pipeline is connected between the BOG gas phase space inside the liquid storage pipe and the first medium pipeline; a third pneumatic control valve is installed on the fourth medium pipeline;

[0019] The controller controls the opening and closing of the third pneumatic control valve.

[0020] Preferably, it further includes a fifth medium pipeline. The first end of the fifth medium pipeline is connected to the liquid phase space inside the liquid storage tank, the second end is connected to the BOG gas phase space inside the liquid storage tank, and at least a part of the fifth medium pipeline is located outside the liquid storage tank;

[0021] A first pneumatic stop valve and a self-pressurizing heat exchange coil are installed on the fifth medium pipeline. Both the first pneumatic stop valve and the self-pressurizing heat exchange coil are located outside the liquid storage tank, and the first pneumatic stop valve is closer to the first end of the fifth medium pipeline than the self-pressurizing heat exchange coil;

[0022] A liquid discharge pipeline, one end of which is connected to the liquid phase space inside the liquid storage tank, and a second pneumatic stop valve is installed on the liquid discharge pipeline;

[0023] The safety monitoring and control system further includes a liquid level sensor for detecting the liquid level height of the LNG in the liquid storage tank;

[0024] The safety monitoring and control system is used to control the opening and closing of the first pneumatic stop valve and the second pneumatic stop valve.

[0025] The present invention also provides a safety protection method for the gas-phase common pipe based on the above-mentioned safety protection system for the gas-phase common pipe, which specifically includes the following steps:

[0026] S1: When the first pressure sensor detects that the pressure value in the BOG gas phase space of the LNG tank container is greater than a first predetermined value, the controller controls the alarm to be turned on, and manually inserts the first male connector and the first female connector and opens the first manual stop valve; the BOG in the LNG tank container enters the main medium pipeline;

[0027] S2: When the pressure value detected by the second pressure sensor is greater than a second predetermined value, the controller opens the second pneumatic control valve, and the BOG in the main medium pipeline flows into the BOG re-liquefaction recovery system;

[0028] After the BOG flows into the BOG re-liquefaction recovery system, the controller turns on the regenerative refrigerator for refrigeration. After the BOG flows through the cryogenic heat exchanger, it is liquefied into LNG and sprayed into the liquid storage tank through the spray head.

[0029] S3: When the pressure value in the main medium pipeline is greater than the fourth predetermined value, the safety valve automatically opens, and the BOG in the main medium pipeline flows into the mast ignition system.

[0030] After the BOG flows into the mast ignition system, the controller controls the igniter to turn on and ignite the BOG at the outlet of the mast exhaust pipe.

[0031] Preferably, between S1 and S2, there is also S11: The controller controls the first pneumatic regulating valve to open, and the BOG in the main medium pipeline flows into the natural gas power system.

[0032] Between S2 and S3, there is also S21: When the difference between the second pressure sensor and the third pressure sensor is less than the third predetermined value, the controller controls the third pneumatic regulating valve to open, and the BOG in the liquid storage tank is introduced into the natural gas power system.

[0033] After the BOG flows into the natural gas power system, the BOG first exchanges heat through the cold energy recovery device, and then flows into the combustion system for combustion to drive the gas turbine to operate; in the cold energy recovery device, the BOG in the first medium pipeline exchanges heat with the air pipeline of the internal gas turbine, the cold air system pipeline of the tank container ship, and the exhaust gas and circulating cooling water pipeline of the gas turbine.

[0034] Preferably, after S3, there is also S4: When the liquid level sensor detects that the liquid level height of the LNG in the liquid storage tank reaches the fifth predetermined value, the controller controls the regenerative refrigerator, the second pneumatic regulating valve, and the third pneumatic regulating valve to close, and controls the first pneumatic stop valve and the second pneumatic stop valve to open; the LNG in the liquid storage tank flows out of the liquid storage tank through the liquid outlet pipeline for long-term storage.

[0035] The beneficial effect of the present invention is that when the pressure value in a certain LNG tank container is greater than the preset value (such as 0.5 MPa), the alarm is activated to prompt the staff to connect the LNG tank container to the main medium pipeline to achieve gas-phase co-management, and through the triple safety protection of the natural gas power system, the BOG re-liquefaction recovery system, and the mast ignition system, ensure the storage and transportation safety of LNG, achieve the maximum utilization and recovery of BOG, and reduce the pollution to the atmospheric environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below with reference to the drawings and embodiments.

[0037] Figure 1 It is a schematic structural diagram of a safety protection system with a gas-phase common pipe in the present invention.

[0038] In the figure, 1 is the LNG storage system, 101 is the LNG tank container, 102 is the first female joint, 103 is the first connecting pipe, 104 is the first manual stop valve, 2 is the natural gas power system, 201 is the combustion system, 202 is the cold energy recovery device, 203 is the gas turbine air pipeline, 204 is the cold air system pipeline of the tank container transport ship, 205 is the gas turbine exhaust and circulating cooling water pipeline, 206 is the first medium pipeline, 3 is the BOG re-liquefaction recovery system, 301 is the regenerative refrigerator, 302 is the low-temperature heat exchanger, 303 is the third manual stop valve, 304 is the second manual stop valve, 305 is the second pneumatic regulating valve, 306 is the third medium pipeline, 307 is the second medium pipeline, 4 is the safety monitoring and control system, 401 is the first pressure sensor, 402 is the second pressure sensor, 403 is the controller, 404 is the alarm, 405 is the third pressure sensor, 406 is the liquid level sensor, 5 is the re-liquefied BOG storage system, 501 is the spray head, 502 is the liquid storage tank, 503 is the third pneumatic regulating valve, 504 is the fourth medium pipeline, 505 is the self-pressurizing heat exchange coil, 506 is the first pneumatic stop valve, 507 is the liquid outlet pipeline, 508 is the second pneumatic stop valve, 509 is the fifth medium pipeline, 6 is the main pipeline system, 601 is the main medium pipeline, 602 is the first male joint, 603 is the second connecting hose, 604 is the first pneumatic regulating valve, 7 is the mast ignition system, 701 is the safety valve, 702 is the mast exhaust pipe, 703 is the igniter. Detailed implementation manners

[0039] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0041] In addition, terms such as "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0042] As Figure 1 shown, the present invention provides a safety protection system for gas-phase co-management, including:

[0043] The LNG storage system 1, the LNG storage system 1 includes at least ten groups of tank container systems, and the tank container system includes an LNG tank container 101 storing LNG. The first male joint 102 is connected to the BOG gas phase space inside the LNG tank container 101 through the first connecting pipe 103. An alarm 404 is provided on the LNG tank container 101. Specifically, the alarm 404 is an audible and visual alarm. A first manual stop valve 104 is installed on the first connecting pipe 103.

[0044] The main pipeline system 6, the main pipeline system 6 includes a main medium pipeline 601 and a plurality of first male joints 602 that match the first female joint 102. Each first male joint 602 is connected to the main medium pipeline 601 through a second connecting hose 603. When the first female joint 102 is inserted into the first male joint 602, the corresponding first connecting pipe 103 and the second connecting hose 603 are connected. In a specific embodiment, the first female joint 102 is a Bayonet cryogenic joint female head, and the first male joint 602 is a Bayonet cryogenic joint male head. Each LNG tank container 101 can be connected to the main medium pipeline 601 through the Bayonet cryogenic joint, realizing the gas-phase co-management of BOG in multiple LNG tank containers 101. When the first manual stop valve 104 is closed, it ensures that the gas in the LNG tank container 101 will not leak, improving safety.

[0045] The safety monitoring and control system 4, the safety monitoring and control system 4 includes a controller 403, a first pressure sensor 401, and a second pressure sensor 402.

[0046] The first pressure sensor 401 is used to detect the pressure value of the BOG gas phase space in the LNG tank container 101; the second pressure sensor 402 is used to detect the pressure value of BOG in the main medium pipeline 601.

[0047] The controller 403 is used to receive the pressure value data sent by the first pressure sensor 401 and the second pressure sensor 402 and control the opening and closing of the audible and visual alarm 404.

[0048] The BOG re-liquefaction recovery system 3 includes a recuperative refrigerator 301, and a cryogenic heat exchanger 302 is included in the recuperative refrigerator 301. The second medium pipeline 307 is connected between the inlet of the cryogenic heat exchanger 302 and the main medium pipeline 601. The connection point of the second medium pipeline 307 and the main medium pipeline 601 is located between the first end and the second end of the main medium pipeline 601. A second pneumatic regulating valve 305 is installed on the second medium pipeline 307, and the controller 403 controls the opening and closing of the recuperative refrigerator 301 and the second pneumatic regulating valve 305. It should be noted that there can be one or more groups of re-liquefaction recovery systems.

[0049] In this embodiment, a second manual stop valve 304 is installed on the second medium pipeline 307, and a third manual stop valve 303 is installed on the third medium pipeline 306. When the re-liquefaction recovery system does not need to work or needs to be repaired or replaced, the second manual stop valve 304 and the third manual stop valve 303 in the re-liquefaction recovery system are closed to ensure safety.

[0050] The re-liquefied BOG storage system 5, the re-liquefied BOG storage system includes a spray head 501 and a liquid storage tank 502. The spray head 501 is arranged inside the liquid storage tank 502 and at the top of the liquid storage tank 502. The spray head 501 has an inlet extending out of the liquid storage tank 502. The third medium pipeline 306 is connected between the inlet of the spray head 501 and the outlet of the cryogenic heat exchanger 302. The BOG flows into the cryogenic heat exchanger 302 along the second medium pipeline 307 and absorbs cold, and the temperature gradually decreases until it is liquefied into LNG. The LNG converges and enters the third medium pipeline 306 and then flows to the spray head 501. The spray head 501 disperses and sprays the LNG into the liquid storage tank 502. The LNG exchanges heat with the BOG in the liquid storage tank 502 during the falling process, reducing the gas temperature, and a part of the BOG in the liquid storage tank 502 is re-liquefied, achieving the purpose of reducing the pressure in the gas phase space of the BOG in the liquid storage tank 502.

[0051] According to another embodiment, this gas-phase co-pipe safety protection system further includes a natural gas power system 2. The natural gas power system 2 includes a combustion system 201 and a cold energy recovery device 202. The combustion system 201 is used to burn BOG to drive the gas turbine to operate. The first medium pipeline 206 is connected between the inlet of the combustion system 201 and the first end of the main medium pipeline 601.

[0052] The cold energy recovery device 202 is used to achieve heat exchange between the first medium pipeline 206, the internal gas turbine air pipeline 203, the cold air system pipeline 204 of the tank container carrier, and the gas turbine exhaust and circulating cooling water pipeline 205. A first pneumatic regulating valve 604 is provided on the main medium pipeline 601. The first pneumatic regulating valve 604 is close to the first end of the main medium pipeline 601. The controller 403 controls the opening or closing of the first pneumatic regulating valve 604. The cold energy recovery device 202 is used to recover the cold energy in the BOG, and is used to reduce the air inlet temperature of the gas turbine unit, cool the exhaust gas temperature of the gas turbine and the circulating cooling water system, improve the efficiency of the unit, and can provide cold energy to the cold air system of the tank container carrier, avoiding a large amount of energy consumption for work refrigeration. Specifically, the cold energy recovery device 202 is a heat exchanger with multiple inlets and multiple outlets. The cold energy recovery device 202 is installed in the first medium pipeline 206, the internal gas turbine air pipeline 203, the cold air system pipeline 204 of the tank container carrier, and the gas turbine exhaust and circulating cooling water pipeline 205 through different inlets and outlets.

[0053] According to another embodiment, the safety monitoring and control system 4 further includes a third pressure sensor 405. The third pressure sensor 405 is used to detect the pressure value in the BOG gas phase space inside the liquid storage tank 502. A fourth medium pipeline 504 is connected to the BOG gas phase space inside the liquid storage pipe and the first medium pipeline 206. A third pneumatic regulating valve 503 is installed on the fourth medium pipeline 504. The controller 403 controls the opening and closing of the third pneumatic regulating valve 503.

[0054] After the third regulating valve is opened, the BOG in the liquid storage tank 502 flows into the first medium pipeline 206 through the fourth medium pipeline 504 and then enters the natural gas power system 2 for combustion use.

[0055] According to another embodiment, such a safety protection system for gas-phase co-pipes further includes: a fifth medium pipeline 509. The first end of the fifth medium pipeline 509 is connected to the liquid phase space inside the liquid storage tank 502, the second end is connected to the BOG gas phase space inside the liquid storage tank 502, and at least a part of the fifth medium pipeline 509 is located outside the liquid storage tank 502.

[0056] A first pneumatic stop valve 506 and a self-pressurizing heat exchange coil 505 are installed on the fifth medium pipeline 509. Both the first pneumatic stop valve 506 and the self-pressurizing heat exchange coil 505 are located outside the liquid storage tank 502, and the first pneumatic stop valve 506 is closer to the first end of the fifth medium pipeline 509 than the self-pressurizing heat exchange coil 505.

[0057] The liquid outlet pipeline 507, one end of the liquid outlet pipeline 507 is connected to the liquid phase space in the liquid storage tank 502, and the other end communicates with a container (such as a liquefied gas tank) capable of storing LNG for a long time. A second pneumatic stop valve 508 is installed on the liquid outlet pipeline 507.

[0058] The safety monitoring and control system 4 further includes a liquid level sensor 406, and the liquid level sensor 406 is used to detect the liquid level height of LNG in the liquid storage tank 502.

[0059] The safety monitoring and control system 4 is used to control the opening and closing of the first pneumatic stop valve 506 and the second pneumatic stop valve 508.

[0060] When the liquid level sensor 406 detects that the LNG in the liquid storage tank 502 reaches a predetermined value, the controller 403 controls the regenerative refrigerator 301, the second pneumatic regulating valve 305 and the third pneumatic regulating valve 503 to close and controls the opening of the first pneumatic stop valve 506 and the second pneumatic stop valve 508. The LNG in the liquid storage tank 502 flows into the fifth medium pipeline 509, is vaporized after receiving heat through the self-pressurizing heat exchange coil 505, and the vaporized LNG flows into the gas phase space of the liquid storage tank 502, so that the pressure in the liquid storage tank 502 increases, and the LNG in the liquid storage tank 502 is pressed through the liquid outlet pipeline 507 to a container (such as a liquefied gas tank) capable of storing LNG for long-term storage.

[0061] According to another embodiment, this safety protection system for gas-phase co-management further includes a mast ignition system 7. The mast ignition system 7 includes a safety valve 701, a mast exhaust pipe 702 and an igniter 703. The second end of the main medium pipeline 601 is connected to the inlet of the mast exhaust pipe 702, and the outlet of the mast exhaust pipe 702 communicates with the outside. The igniter 703 is arranged at the outlet of the mast exhaust pipe 702. The safety valve 701 is arranged at the second end of the main medium pipeline 601. The controller 403 controls the ignition of the igniter 703.

[0062] When the pressure in the main medium pipeline 601 is greater than the set value of the safety valve 701, the safety valve 701 automatically opens, the BOG in the main medium pipeline 601 flows into the mast exhaust pipe 702, and is discharged after being ignited by the igniter 703 arranged at the outlet of the mast exhaust pipe 702.

[0063] When the pressure value in a certain LNG tank container 101 is greater than a preset value (such as 0.5 MPa) in this safety protection system for gas-phase co-management, the alarm 404 prompts the staff to connect the LNG tank container 101 to the main medium pipeline 601, realizing gas-phase co-management. After gas-phase co-management, the BOG in the main medium pipeline 601 can be led out for disposal, ensuring the safety protection of the BOG.

[0064] This gas-phase co-management safety protection system can be applied to the transport ship of the LNG tank container 101 or the storage yard where the LNG tank containers 101 are stacked.

[0065] This gas-phase co-management safety protection system has a triple safety protection function. When the pressure of the LNG tank container 101 is higher than 0.5 MPa, the gas phase space of the LNG tank container 101 is connected to the main medium pipeline 601 to achieve gas-phase co-management. First, the BOG in the main medium pipeline 601 is introduced into the natural gas power system 2 and used as fuel for combustion. When the natural gas power system 2 cannot consume it, the BOG re-liquefaction recovery system 3 liquefies the BOG. When the BOG in the main medium pipeline 601 is over-pressurized, the BOG in the main medium pipeline 601 enters the mast ignition system 7 and is ignited and discharged to ensure the safety of the entire system.

[0066] The present invention also provides a gas-phase co-management safety protection method based on the above-mentioned gas-phase co-management safety protection system, which specifically includes the following steps:

[0067] S1: When the first pressure sensor 401 detects that the pressure value of the BOG gas phase space in the LNG tank container 101 is greater than the first predetermined value (such as 0.5 MPa), the controller 403 controls the alarm 404 to be turned on. Manually insert the first male connector 602 into the first female connector 102 and open the first manual stop valve 104, and the BOG in the LNG tank container 101 enters the main medium pipeline 601.

[0068] S2: When the pressure value detected by the second pressure sensor 402 is greater than the second predetermined value, the controller 403 opens the second pneumatic regulating valve 305, and the BOG in the main medium pipeline 601 flows into the BOG re-liquefaction recovery system 3.

[0069] After the BOG flows into the BOG re-liquefaction recovery system 3, the controller 403 turns on the regenerative refrigerator 301 for refrigeration. The BOG is liquefied into LNG after flowing through the low-temperature heat exchanger 302 and is sprayed into the liquid storage tank 502 through the spray head 501.

[0070] S3: When the pressure value in the main medium pipeline 601 is greater than the fourth predetermined value, the safety valve 701 automatically opens, and the BOG in the main medium pipeline 601 flows into the mast ignition system 7. When the BOG flows into the mast ignition system 7, the controller 403 controls the igniter 703 to be turned on to ignite the BOG at the outlet of the mast exhaust pipe 702.

[0071] According to another embodiment, between S1 and S2, there is also S11: The controller 403 controls the first pneumatic regulating valve 604 to be opened, and the BOG in the main medium pipeline 601 flows into the natural gas power system 2.

[0072] Between S2 and S3, S21 is further included: when the difference between the second pressure sensor 402 and the third pressure sensor 405 is less than a third predetermined value, the controller 403 controls the third pneumatic regulating valve 503 to open, and introduces the BOG in the liquid storage tank 502 into the natural gas power system 2.

[0073] After the BOG flows into the natural gas power system 2, the BOG first exchanges heat through the cold energy recovery device 202, and then flows into the combustion system 201 for combustion to drive the gas turbine to operate; in the cold energy recovery device 202, the BOG in the first medium pipeline 206 exchanges heat with the internal gas turbine air pipeline 203, the tank container ship cold air system pipeline 204, and the gas turbine exhaust and circulating cooling water pipeline 205.

[0074] According to another embodiment, after S3, S4 is further included: when the liquid level sensor 406 detects that the liquid level height of the LNG in the liquid storage tank 502 reaches a fifth predetermined value, the controller 403 controls the regenerative refrigerator 301, the second pneumatic regulating valve 305, and the third pneumatic regulating valve 503 to close and controls the first pneumatic stop valve 506 and the second pneumatic stop valve 508 to open; the LNG in the liquid storage tank 502 flows out of the liquid storage tank 502 through the liquid outlet pipeline 507 for long-term storage.

[0075] When this gas phase co-management safety protection method is applied to an LNG carrier, when the pressure of the LNG tank container 101 is higher than 0.5 MPa, the gas phase space of the LNG tank container 101 is connected to the main medium pipeline 601 to achieve gas phase co-management. First, the BOG in the main medium pipeline 601 is introduced into the natural gas power system 2 and used as fuel for combustion. When the natural gas power system 2 cannot consume it, the BOG re-liquefaction recovery system 3 is started to liquefy and recover the BOG. When the BOG in the main medium pipeline 601 is overpressured, the safety valve 701 automatically jumps up, and the BOG in the main medium pipeline 601 is ignited and depressurized through the mast ignition system 7 to ensure the safety of the entire system.

[0076] When this gas phase co-management safety protection method is applied to a storage yard, the entire device does not have a natural gas power system 2. After gas phase co-management, the BOG in the main medium pipeline 601 is preferentially liquefied and recovered by the re-liquefaction system. When the BOG in the main medium pipeline 601 is overpressured, the safety valve 701 automatically jumps up, and the BOG in the main medium pipeline 601 is ignited and depressurized through the combustion ignition system.

[0077] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0078] Enlightened by the above ideal embodiments of the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A safety protection method for gas co-management of a safety protection system based on gas co-management. The safety protection system for gas co-management includes: An LNG storage system (1), where the LNG storage system (1) includes at least ten tank container systems. The tank container system includes an LNG tank container (101) storing LNG; a first female joint (102) is connected to the BOG gas phase space inside the LNG tank container (101) through a first connecting pipe (103); an alarm (404) is provided on the LNG tank container (101); a first manual stop valve (104) is installed on the first connecting pipe (103); A main pipeline system (6), where the main pipeline system (6) includes a main medium pipeline (601) and a plurality of first male joints (602) matching the first female joint (102). Each first male joint (602) is connected to the main medium pipeline (601) through a second connecting hose (603); when the first female joint (102) is inserted into the first male joint (602), the corresponding first connecting pipe (103) and second connecting hose (603) are connected; A safety monitoring and control system (4), where the safety monitoring and control system (4) includes a controller (403), a first pressure sensor (401), and a second pressure sensor (402); A BOG re-liquefaction recovery system (3), where the BOG re-liquefaction recovery system (3) includes a regenerative refrigerating machine (301). The regenerative refrigerating machine (301) includes a cryogenic heat exchanger (302); a second medium pipeline (307) is connected between the inlet of the cryogenic heat exchanger (302) and the main medium pipeline (601); the connection point of the second medium pipeline (307) and the main medium pipeline (601) is located between the first end and the second end of the main medium pipeline (601); a second pneumatic regulating valve (305) is installed on the second medium pipeline (307), and the controller (403) controls the opening or closing of the regenerative refrigerating machine (301) and the second pneumatic regulating valve (305); A re-liquefied BOG storage system, where the re-liquefied BOG storage system includes a spray head (501) and a liquid storage tank (502). The spray head (501) is arranged inside the liquid storage tank (502) and at the top of the liquid storage tank (502). The spray head (501) has an inlet extending out of the liquid storage tank (502); a third medium pipeline (306) is connected between the inlet of the spray head (501) and the outlet of the cryogenic heat exchanger (302); The first pressure sensor (401) is used to detect the pressure value of the BOG gas phase space inside the LNG tank container (101); the second pressure sensor (402) is used to detect the pressure value of BOG in the main medium pipeline (601); The controller (403) is used to receive the pressure value data sent by the first pressure sensor (401) and the second pressure sensor (402) and control the opening and closing of the alarm (404); Mast ignition system (7), the mast ignition system (7) includes a safety valve (701), a mast exhaust pipe (702) and an igniter (703). The second end of the main medium pipeline (601) is connected to the inlet of the mast exhaust pipe (702), and the outlet of the mast exhaust pipe (702) communicates with the outside; the igniter (703) is arranged at the outlet of the mast exhaust pipe (702); the safety valve (701) is arranged at the second end of the main medium pipeline (601); the controller (403) controls the ignition of the igniter (703). The safety protection system of the gas-phase co-management also includes a natural gas power system (2), and the natural gas power system (2) includes a combustion system (201) and a cold energy recovery device (202); the combustion system (201) is used to burn BOG to drive the gas turbine to operate; a first medium pipeline (206) is connected between the inlet of the combustion system (201) and the first end of the main medium pipeline (601); a first pneumatic control valve (604) is arranged on the main medium pipeline (601), and the first pneumatic control valve (604) is close to the first end of the main medium pipeline (601); the controller (403) controls the opening or closing of the first pneumatic control valve (604). The cold energy recovery device (202) is a heat exchanger with multiple inlets and multiple outlets, and the heat exchanger is installed in the first medium pipeline (206), the internal gas turbine air pipeline (203), the cold air system pipeline (204) of the tank container ship and the gas turbine exhaust and circulating cooling water pipeline (205) through different inlets and outlets. The safety monitoring and control system (4) also includes a third pressure sensor (405), and the third pressure sensor (405) is used to detect the pressure value of the BOG gas phase space inside the liquid storage tank (502). A fourth medium pipeline (504) is connected between the BOG gas phase space inside the liquid storage tank and the first medium pipeline (206); a third pneumatic control valve (503) is installed on the fourth medium pipeline (504). The controller (403) controls the opening and closing of the third pneumatic control valve (503). The safety protection method of the gas-phase co-management specifically includes the following steps: S1: When the first pressure sensor (401) detects that the pressure value of the BOG gas phase space in the LNG tank container (101) is greater than the first predetermined value, the controller (403) controls the alarm (404) to turn on, and manually inserts the first male connector (602) and the first female connector (102), and opens the first manual stop valve (104); the BOG in the LNG tank container (101) enters the main medium pipeline (601). S2: When the pressure value detected by the second pressure sensor (402) is greater than the second predetermined value, the controller (403) opens the second pneumatic control valve (305), and the BOG in the main medium pipeline (601) flows into the BOG re-liquefaction recovery system (3). After the BOG flows into the BOG re-liquefaction recovery system (3), the controller (403) turns on the regenerative refrigerator (301) for refrigeration. After the BOG flows through the cryogenic heat exchanger (302), it is liquefied into LNG and sprayed into the liquid storage tank (502) through the spray head (501). S3: When the pressure value in the main medium pipeline (601) is greater than the fourth predetermined value, the safety valve (701) automatically opens, and the BOG in the main medium pipeline (601) flows into the mast ignition system (7). After the BOG flows into the mast ignition system (7), the controller (403) controls the igniter (703) to turn on and ignite the BOG at the outlet of the mast exhaust pipe (702). Between S1 and S2, there is also S11: The controller (403) controls the first pneumatic control valve (604) to open, and the BOG in the main medium pipeline (601) flows into the natural gas power system (2). Between S2 and S3, there is also S21: When the difference between the second pressure sensor (402) and the third pressure sensor (405) is less than the third predetermined value, the controller (403) controls the third pneumatic control valve (503) to open and introduces the BOG in the liquid storage tank (502) into the natural gas power system (2).

2. The safety protection method for gas-phase co-management according to claim 1, characterized in that: The safety protection system for gas-phase co-management further includes a fifth medium pipeline (509). The first end of the fifth medium pipeline (509) is connected to the liquid phase space in the liquid storage tank (502), the second end is connected to the BOG gas phase space in the liquid storage tank (502), and at least a part of the fifth medium pipeline (509) is located outside the liquid storage tank (502). A first pneumatic stop valve (506) and a self-pressurizing heat exchange coil (505) are installed on the fifth medium pipeline (509). The first pneumatic stop valve (506) and the self-pressurizing heat exchange coil (505) are both located outside the liquid storage tank (502), and the first pneumatic stop valve (506) is closer to the first end of the fifth medium pipeline (509) than the self-pressurizing heat exchange coil (505). A liquid outlet pipeline (507), one end of the liquid outlet pipeline (507) is connected to the liquid phase space in the liquid storage tank (502), and a second pneumatic stop valve (508) is installed on the liquid outlet pipeline (507). The safety monitoring and control system (4) further includes a liquid level sensor (406), and the liquid level sensor (406) is used to detect the liquid level height of the LNG in the liquid storage tank (502). The safety monitoring and control system (4) is used to control the opening and closing of the first pneumatic stop valve (506) and the second pneumatic stop valve (508).

3. The safety protection method for gas-phase co-management according to claim 2, characterized in that: After the BOG flows into the natural gas power system (2), the BOG first exchanges heat through the cold energy recovery device (202), and then flows into the combustion system (201) for combustion to drive the gas turbine to operate; in the cold energy recovery device (202), the BOG in the first medium pipeline (206) exchanges heat with the internal gas turbine air pipeline (203), the cold air system pipeline (204) of the tank ship, and the gas turbine exhaust and circulating cooling water pipeline (205).

4. The safety protection method for gas-phase co-management according to claim 3, wherein: After S3, S4 is further included: when the liquid level sensor (406) detects that the liquid level height of the LNG in the liquid storage tank (502) reaches the fifth predetermined value, the controller (403) controls the regenerative refrigerator (301), the second pneumatic regulating valve (305), and the third pneumatic regulating valve (503) to close, and controls the first pneumatic stop valve (506) and the second pneumatic stop valve (508) to open; the LNG in the liquid storage tank (502) flows out of the liquid storage tank (502) through the liquid outlet pipeline (507) for long-term storage.

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