Fire extinguishing method and fire extinguishing system for low-boiling-point flammable liquid storage tank

Abstract

The invention discloses a fire extinguishing method for a low-boiling-point flammable liquid storage tank. Fire control and cooling: applying high-stability compressed air foam to quickly control the fire of the low-boiling-point flammable liquid aiming at the fire of the low-boiling-point flammable liquid storage tank, and covering the surface of the low-boiling-point flammable liquid to form a foam blanket, so that the liquid is gradually cooled until the boiling point of the low-boiling-point flammable liquid is lower than the boiling point of the low-boiling-point flammable liquid; only oil steam and residual flames on the surface of the foam blanket remain; fire extinguishing: quickly spraying and releasing a dry powder extinguishing agent aiming at low-boiling-point flammable liquid oil steam residual flames on the surface of the foam blanket, and completely extinguishing the oil steam residual flames on the surface of the foam blanket by utilizing the excellent chemical inhibition fire extinguishing performance of the dry powder extinguishing agent; and after the fire of the low-boiling-point flammable liquid storage tank is completely extinguished, high-stability compressed air foam is continuously applied, a foam blanket is formed on the surface of the low-boiling-point flammable liquid, the low-boiling-point flammable liquid is continuously cooled, and reburning is effectively prevented. The fire extinguishing method is very efficient for extinguishing a low-boiling-point flammable liquid fire source.

Description

Technical Field

[0001] The invention relates to a fire extinguishing method and a fire extinguishing system for a low-boiling-point flammable liquid storage tank, belonging to the technical field of fire extinguishing for low-boiling-point flammable liquid storage tanks. Background Art

[0002] The petrochemical industry is a pillar industry of my country's national economy. With the intensive, refined and gigantic development of petrochemicals, my country has planned and built more than 20 national petrochemical industrial parks, and built more than 20 large ethylene projects represented by the 1 million tons / year ethylene project of Sinopec (Tianjin) Petrochemical. A large number of low-boiling flammable liquid storage tanks with high fire risks and difficult fire fighting, such as naphtha, condensate, and light-reforming liquid, have emerged, and the capacity of a single tank is getting larger and larger, gradually developing from the current common 5,000 m3 and 10,000 m3 to 20,000 m3 or even larger capacity, and the fire prevention and control situation is becoming increasingly severe. Low-boiling-point flammable liquids with boiling points below 45°C, such as naphtha, condensate, and light reforming liquid, have low surface tension, and conventional aqueous film-forming foams cannot play the role of covering, isolating, and extinguishing fires by water films. In addition, low-boiling-point flammable liquids are highly volatile, and their saturated vapor pressure is more than 10 times that of conventional n-heptane liquid fuel. Conventional aqueous film-forming, protein, and anti-solvent foams cannot inhibit their rapid volatilization, and oil vapor can penetrate the foam layer to form a residual flame that continues to burn and constantly changes in position and size. Therefore, conventional foam and water film covering effects cannot meet the fire extinguishing needs of low-boiling-point flammable liquid storage tanks. There are problems such as difficulty in extinguishing fires, easy re-ignition, and the inability of existing single foam fire extinguishing technology to effectively deal with them.

[0003] Compressed air foam produced by positive pressure has the characteristics of uniform and fine foam structure, high foam stability, strong fire extinguishing ability and high efficiency. It can quickly and effectively extinguish fires under complex conditions such as Class A fire, Class B fire, Class AB mixed fire and three-dimensional shielding fire, and at the same time has good thermal insulation protection performance, anti-reignition performance and cooling and cooling capabilities. However, conventional single compressed air foam mainly performs physical fire extinguishing through isolation and cooling of highly stable foam, and does not have chemical suppression fire extinguishing effect. It takes a long time to extinguish the residual flame of low-boiling point flammable liquid vapor only through physical fire extinguishing effect, with weak ability and low efficiency, and cannot fully meet the actual fire extinguishing needs of low-boiling point flammable liquid storage tanks.

[0004] Dry powder and ultrafine dry powder fire extinguishing agents extinguish fires by adsorbing and converting combustion reaction free radicals on the surface of powder particles and by inhibiting and eliminating combustion reaction free radicals by high-temperature decomposition substances. They have the outstanding characteristics of high fire extinguishing efficiency and fast speed, and can quickly extinguish flaming fires. However, dry powder and ultrafine dry powder fire extinguishing agents mainly extinguish fires by chemical inhibition, and have limited cooling and temperature reduction effects, poor anti-reignition ability, and are prone to re-ignition when fighting fires in low-boiling-point flammable liquid storage tanks.

[0005] There is an urgent need for a fire extinguishing device with a simple structure and integrated layout, which has both foam and dry powder functions. The fire extinguishing medium can be adjusted at any time according to the needs of fire extinguishing, and it is an easy-to-use solution that fully utilizes the dual physical and chemical effects to effectively extinguish low-boiling point flammable liquids. Summary of the invention

[0006] In view of the deficiencies of the above-mentioned prior art, a method and a fire extinguishing system for low-boiling-point flammable liquid storage tanks are disclosed, which have strong isolation, covering and cooling capabilities, high fire extinguishing efficiency, fast speed, and excellent anti-reignition performance. The method and the fire extinguishing system can quickly cover and control low-boiling-point flammable liquid fires with foam, continuously cool them, and quickly extinguish residual flames of oil vapor, thereby completely extinguishing low-boiling-point flammable liquid storage tank fires. Both fixed fire extinguishing systems and mobile fire extinguishing equipment can be used.

[0007] According to an embodiment of the present invention, a first solution is provided:

[0008] A method for extinguishing a fire in a low-boiling-point flammable liquid storage tank, comprising:

[0009] S1. Fire control and cooling: For fires in low-boiling-point flammable liquid storage tanks, high-stability compressed air foam is applied to quickly control the low-boiling-point flammable liquid fire, and a foam blanket is formed on the surface of the low-boiling-point flammable liquid to gradually cool the liquid until it drops below the boiling point of the low-boiling-point flammable liquid, and only the residual flame of oil vapor remains on the surface of the foam blanket;

[0010] S2. Extinguish open flames: For the residual flames of low-boiling-point flammable liquid oil vapor on the surface of the foam blanket, quickly spray and release dry powder fire extinguishing agent, and use the excellent chemical suppression and fire extinguishing performance of dry powder fire extinguishing agent to completely extinguish the residual flames of oil vapor on the surface of the foam blanket;

[0011] S3. Anti-reignition protection: After the fire in the low-boiling-point flammable liquid storage tank is completely extinguished, continue to apply high-stability compressed air foam to form a foam blanket on the surface of the low-boiling-point flammable liquid to continuously cool it down and effectively prevent it from re-igniting.

[0012] Furthermore, the foaming multiple of the high-stability compressed air foam in steps S1 and S3 is greater than or equal to 4 times, the 25% liquid separation time is greater than or equal to 3 minutes, and the foam supply intensity is 5L / (min·m2)~30L / (min·m2);

[0013] The thickness of the foam blanket in step S1 is 100-200 mm, and the foaming time is 1 min to 10 min;

[0014] The dry powder fire extinguishing agent in step S2 is an oil-water dual-repellent dry powder or an ultra-fine dry powder, and the effective injection rate of a single injection device is 1kg / s~30kg / s, and the injection time is 10s~120s;

[0015] In step S3, the time for continuously applying the highly stable compressed air foam is 1 min to 30 min; and the thickness of the foam blanket is 300-1000 mm.

[0016] According to an embodiment of the present invention, using the low-boiling-point flammable liquid storage tank fire extinguishing method in the first embodiment provided by the present invention, a second embodiment is provided:

[0017] A low boiling point flammable liquid storage tank fire extinguishing system, comprising:

[0018] Compressed air foam-powder combined device, fire extinguishing agent delivery pipeline, fire extinguishing agent release device, system controller;

[0019] The compressed air foam and powder fire extinguishing agent generated by the compressed air foam-powder combination device are transported to the fire extinguishing agent release device through the fire extinguishing agent delivery pipeline, and are sprayed through the fire extinguishing agent release device; the system controller controls which fire extinguishing medium the compressed air foam-powder combination device uses and whether to open the fire extinguishing agent release device;

[0020] The compressed air foam-powder combined device adopts a centralized supply type device or an independent supply type device;

[0021] The centralized supply device can generate compressed air foam and powder fire extinguishing agent in stages, and output the compressed air foam and powder fire extinguishing agent in sequence through the common fire extinguishing agent delivery pipeline and output port;

[0022] The independent supply type device can simultaneously generate and output compressed air foam and powder through independent conveying pipelines and output ports, and spray them through the compressed air foam release device and the powder release device respectively.

[0023] Furthermore, the compressed air foam-powder combined device uses a common air source to produce highly stable compressed air foam and powder fire extinguishing agent, and the combined device produces and outputs highly stable compressed air foam and powder fire extinguishing agent. The highly stable compressed air foam and powder fire extinguishing agent are transported through the same or different delivery pipelines and sprayed through the same or different release devices.

[0024] Furthermore, the compressed air foam-powder combined device comprises an air source, a foam generating device, a dry powder supply source and a fire extinguishing agent output port;

[0025] The foam generating device comprises a fire water tank and a fire pump connected to the fire water tank, and a water supply valve is arranged between the fire water tank and the fire pump;

[0026] The foam generating device also includes a foam liquid tank, which is connected to a liquid supply valve, a foam liquid pump and a foam liquid flow meter in sequence through a pipeline.

[0027] The output ends of the fire pump and the foam liquid flowmeter are both connected to the foam mixed liquid flowmeter, one end of the foam mixed liquid flowmeter is connected to a liquid regulating valve, the liquid regulating valve is connected to one inlet of the gas-liquid mixer, and the other inlet is connected to the gas source, and a gas flowmeter and a gas flow regulating valve are also provided on the pipeline connecting the gas-liquid mixer and the gas source;

[0028] The outlet of the gas-liquid mixer is connected to the fire extinguishing agent outlet;

[0029] The dry powder supply source is mainly a powder tank, a powder inlet is arranged in the powder tank, the powder inlet is connected to the powder outlet through a pipeline, and a powder outlet valve is arranged on the pipeline connected to the powder inlet;

[0030] An air inlet is provided at the bottom of the powder tank; the air inlet is connected to an air source, and an air inlet valve is provided between the air inlet and the air source;

[0031] The fire water tank is provided with a water supply valve;

[0032] The foam liquid tank is provided with a liquid replenishing valve;

[0033] The powder tank is provided with a powder filling port.

[0034] Furthermore, when foam and dry powder are used sequentially, the output port of the dry powder supply source may also be shared with the fire extinguishing agent output port of the foam generating device.

[0035] Furthermore, the gas source includes an air compressor and a buffer gas tank connected to the output end of the air compressor. A one-way valve is connected to the output end of the buffer gas tank, and the one-way valve can prevent the fire extinguishing agent from spraying back into the buffer gas tank and the air compressor.

[0036] Furthermore, the compressed air foam-powder combination device is also provided with a central controller connected to an air inlet valve and a powder output valve to control the output of the split body;

[0037] It is connected with a foam liquid pump, a liquid regulating valve and a gas flow regulating valve to control the flow of the foam liquid;

[0038] It is connected with a foam mixed liquid flow meter, a foam liquid flow meter and a gas flow meter to monitor and assist in controlling and regulating the stable generation of foam;

[0039] The central controller adaptively adjusts the flow rate to the set flow rate.

[0040] Furthermore, the fire extinguishing agent release device is configured as more than one arc-shaped tube, with a tube diameter of 10 mm to 200 mm, and a plurality of release holes are evenly opened or a plurality of nozzles are installed on each arc-shaped tube, the flow diameter of the release holes or nozzles is 2 mm to 40 mm, the release holes or nozzles are spaced 100 mm to 2000 mm apart, and the arc-shaped tubes are spaced 100 mm to 500 mm apart, and are made of high temperature resistant metal material;

[0041] The fire extinguishing agent release device is installed on the inner wall of the oil tank top or on the floating plate, and can evenly spray compressed air foam or powder fire extinguishing agent;

[0042] A partition valve is provided on the fire extinguishing agent delivery pipeline connecting the fire extinguishing agent release device and the fire extinguishing agent output port, and the partition valve is used to control the connected fire extinguishing agent release device to release the fire extinguishing agent.

[0043] Furthermore, the fire extinguishing agent release device adopts a compressed air foam release device and a powder release device respectively;

[0044] The compressed air foam releasing device adopts a compressed air foam cannon or a foam gun;

[0045] The powder release device adopts a powder fire monitor or a powder fire gun;

[0046] The fire extinguishing agent outlet is connected to a compressed air foam release device through a foam pipe;

[0047] The powder output port is connected to the powder release device through a dry powder tube;

[0048] A foam control valve is provided on the foam pipe;

[0049] A powder control valve is provided on the dry powder tube.

[0050] Compared with the prior art, the technical solution provided by this application has unique beneficial effects.

[0051] 1. The present invention adopts a fire extinguishing method combining compressed air foam and powder fire extinguishing agent, and applies different fire extinguishing agents in stages and layers through "fire control and cooling - extinguishing open flames - anti-reignition protection". It can give full play to the high-stability compressed air foam's efficient fire control and extinguishing performance for flammable liquid fires and excellent cooling, anti-reignition and heat insulation protection performance, as well as the powder fire extinguishing agent's significant technical advantages of fast fire extinguishing speed and high efficiency for oil vapor fires. It effectively solves the problems of long fire extinguishing time and weak ability of single compressed air foam for oil vapor fires, inability to quickly and completely extinguish low-boiling point flammable liquid fires, and limited cooling and cooling effect of single powder fire extinguishing agent, poor anti-reignition ability, and easy reignition, and solves the problem of extinguishing low-boiling point flammable liquid fires.

[0052] 2. The compressed air foam-powder combined device of the present invention adopts an oil-water dual-repellent dry powder fire extinguishing agent, and can be integrated into an integrated design by sharing a compressed air source, a fire extinguishing delivery pipeline, and a fire extinguishing agent release device. It not only gives full play to the role of the facilities and saves resources, but also can produce high-stability compressed air foam and powder fire extinguishing agents. Different fire extinguishing media will not dissolve each other. It is suitable for fixed fire extinguishing systems and mobile fire trucks, and has the remarkable characteristics of diverse functions, wide application range, and high engineering application value.

[0053] 3. The low-boiling-point flammable liquid storage tank fire extinguishing system of the present invention can apply the functions of compressed air foam and powder fire extinguishing agents in stages and layers, and can also apply the functions of compressed air foam and powder fire extinguishing agents at the same time. It has the remarkable technical characteristics of strong isolation, covering and cooling capabilities, high fire extinguishing efficiency, fast speed, and excellent anti-reignition performance. It can quickly cover and control low-boiling-point flammable liquid fires, continuously cool them down, and can quickly extinguish residual flames of oil vapor, providing advanced and efficient fire extinguishing means for solving the technical problems of low-boiling-point flammable liquid storage tank fire fighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] in:

[0056] Figure 1 A schematic diagram of a process for extinguishing a fire of a low-boiling-point flammable liquid storage tank in one embodiment;

[0057] Figure 2 It is a structural schematic diagram of Embodiment 1 of the fire extinguishing system for a low-boiling-point flammable liquid storage tank;

[0058] Figure 3 This is a schematic structural diagram of a centralized supply type compressed air foam-powder combined device in one embodiment;

[0059] Figure 4 It is a structural schematic diagram of Embodiment 2 of the fire extinguishing system for a low-boiling-point flammable liquid storage tank;

[0060] Figure 5 This is a schematic diagram of the structure of an independent supply type compressed air foam-powder combination device in one embodiment;

[0061] Reference numerals:

[0062] 1Compressed air foam-powder combined device; 1A centralized supply type device; 1B independent supply type device;

[0063] 1-1 Fire water tank; 1-2 Water supply valve; 1-3 Water replenishment valve; 1-4 Fire pump; 1-5 Foam liquid tank; 1-6 Replenishment valve; 1-7 Liquid supply valve; 1-8 Foam liquid pump; 1-9 Foam liquid flow meter; 1-10 Foam mixed liquid flow meter; 1-11 Liquid regulating valve; 1-12 Central controller; 1-13 Gas-liquid mixer; 1-14 Air compressor; 1-15 Buffer gas tank; 1-16 Check valve; 1-17 Gas flow meter; 1-18 Gas flow regulating valve; 1-19 Inlet valve; 1-20 Powder output valve; 1-21 Powder tank; 1-22 Powder inlet; 1-23 Air inlet; 1-24 Powder filling port; 1-25 Fire extinguishing agent output port; 1-26 Powder output port;

[0064] 2 partition valve; 2-1 compressed air foam pipeline control valve; 2-2 powder control valve; 3 fire extinguishing agent delivery pipeline; 4 fire extinguishing agent release device; 5 oil tank; 6 compressed air foam release device; 7 powder release device. DETAILED DESCRIPTION

[0065] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of this application.

[0066] This application proposes a method for extinguishing fire in a low-boiling-point flammable liquid storage tank.

[0067] A method for extinguishing a low-boiling-point flammable liquid storage tank fire, the steps comprising:

[0068] S1. Fire control and cooling: For fires in low-boiling-point flammable liquid storage tanks, high-stability compressed air foam is applied to quickly control the low-boiling-point flammable liquid fire, and a foam blanket is formed on the surface of the low-boiling-point flammable liquid to gradually cool the liquid until it drops below the boiling point of the low-boiling-point flammable liquid, and only residual flames of oil vapor remain on the surface of the foam blanket.

[0069] S2. Extinguish open flames: For the residual flames of low-boiling-point flammable liquid oil vapor on the surface of the foam blanket, quickly spray and release oil- and water-repellent dry powder fire extinguishing agent, and use the excellent chemical inhibition and fire extinguishing performance of the dry powder fire extinguishing agent to completely extinguish the residual flames of oil vapor on the surface of the foam blanket.

[0070] S3. Anti-reignition protection: After the fire in the low-boiling-point flammable liquid storage tank is completely extinguished, continue to apply high-stability compressed air foam to form a foam blanket on the surface of the low-boiling-point flammable liquid to continuously cool it down and effectively prevent it from re-igniting.

[0071] The high-stability compressed air foam in steps S1 and S3 has a foaming multiple greater than or equal to 4 times, a 25% liquid separation time greater than or equal to 3 minutes, and a foam supply intensity of 5 L / (min·m 2 )~30L / (min·m 2 );

[0072] The thickness of the foam blanket in step S1 is 100-200 mm; the foaming time is 1 min to 10 min.

[0073] The dry powder fire extinguishing agent in step S2 is an oil-water dual-repellent dry powder or an ultra-fine dry powder, and the effective injection rate of a single injection device is 1kg / s~30kg / s, and the injection time is 10s~120s;

[0074] In step S3, the time for continuously applying the highly stable compressed air foam is 1 min to 30 min; and the thickness of the foam blanket is 300-1000 mm.

[0075] The present invention also proposes a low-boiling-point flammable liquid storage tank fire extinguishing system using the above-mentioned fire extinguishing method, comprising:

[0076] Compressed air foam-powder combined device 1, fire extinguishing agent delivery pipeline 3, fire extinguishing agent release device 4, system controller;

[0077] The compressed air foam and powder fire extinguishing agent generated by the compressed air foam-powder combination device 1 are transported to the fire extinguishing agent release device 4 through the fire extinguishing agent delivery pipeline 3, and are sprayed through the fire extinguishing agent release device 4; the system controller controls which fire extinguishing medium the compressed air foam-powder combination device 1 uses and whether to open the fire extinguishing agent release device 4.

[0078] The compressed air foam-powder combination device 1 uses a common air compressor 1-14 and a buffer gas tank 1-15 as gas sources to produce highly stable compressed air foam and powder fire extinguishing agent. The combined device produces and outputs highly stable compressed air foam and powder fire extinguishing agent. The highly stable compressed air foam and powder fire extinguishing agent are transported through the same or different delivery pipelines and are sprayed through the same or different release devices.

[0079] The compressed air foam-powder combined device 1 is divided into two types: centralized supply type and independent supply type.

[0080] The centralized supply type device 1A can generate compressed air foam and powder fire extinguishing agent in stages, and output the compressed air foam and powder fire extinguishing agent in sequence through the common fire extinguishing agent delivery pipeline 3 and the output port;

[0081] The independent supply type device 1B can simultaneously generate and output compressed air foam and powder through independent conveying pipes and output ports, and spray them through the compressed air foam release device 6 and the powder release device 7 respectively.

[0082] The compressed air foam-powder combined device 1 comprises an air source, a foam generating device, a dry powder supply source and a fire extinguishing agent output port 1-25.

[0083] The gas source includes an air compressor 1-14 and a buffer gas tank 1-15 connected to the output end of the air compressor 1-14. A one-way valve 1-16 is connected to the output end of the buffer gas tank 1-15. The one-way valve 1-16 can prevent the fire extinguishing agent from spraying back into the buffer gas tank 1-15 and the air compressor 1-14.

[0084] The foam generating device comprises a fire water tank 1-1, a fire pump 1-4 connected to the fire water tank 1-1, and a water supply valve 1-2 is arranged between the fire water tank 1-1 and the fire pump 1-4;

[0085] The foam generating device also includes a foam liquid tank 1-5, which is connected to a liquid supply valve 1-7, a foam liquid pump 1-8 and a foam liquid flow meter 1-9 in sequence through pipelines.

[0086] The output ends of the fire pump 1-4 and the foam liquid flowmeter 1-9 are both connected to the foam mixed liquid flowmeter 1-10, one end of the foam mixed liquid flowmeter 1-10 is connected to the liquid regulating valve 1-11, the liquid regulating valve 1-11 is connected to one inlet of the gas-liquid mixer 1-13, and the other inlet is connected to the gas source, and a gas flowmeter 1-17 and a gas flow regulating valve 1-18 are also provided on the pipeline connecting the gas-liquid mixer 1-13 and the gas source;

[0087] The outlet of the gas-liquid mixer 1-13 is connected to the fire extinguishing agent outlet 1-25;

[0088] The fire water tank 1-1 is provided with a water supply valve 1-3.

[0089] The foam liquid tank 1-5 is provided with a liquid replenishing valve 1-6;

[0090] A dry powder supply source, the main body of which is a powder tank 1-21, a powder inlet 1-22 is arranged in the powder tank 1-21, the powder inlet 1-22 is connected to a powder outlet 1-26 through a pipeline, and a powder outlet valve 1-20 is arranged on the pipeline connected to the powder inlet 1-22;

[0091] An air inlet 1-23 is provided at the bottom of the powder tank 1-21; the air inlet 1-23 is connected to an air source, and an air inlet valve 1-19 is provided between the air inlet 1-23 and the air source;

[0092] The powder tank 1-21 is provided with a powder filling port 1-24;

[0093] When foam and dry powder are used in sequence, the powder outlet 1-26 of the dry powder supply source can also directly use the fire extinguishing agent outlet 1-25 of the foam generating device. That is to say, only one fire extinguishing agent outlet 1-25 is provided, and the foam generating device and the dry powder supply source share one outlet.

[0094] The compressed air foam-powder combination device 1 is also provided with a central controller 1-12, which is connected to an air inlet valve 1-19 and a powder output valve 1-20 to control the output of the powder;

[0095] It is connected with a foam liquid pump 1-8, a liquid regulating valve 1-11 and a gas flow regulating valve 1-18 to control the flow of the foam liquid;

[0096] It is connected with a foam mixed liquid flow meter 1-10, a foam liquid flow meter 1-9 and a gas flow meter 1-17, and is used for monitoring and auxiliary control to adjust the stable generation of foam;

[0097] The central controller 1-12 adaptively adjusts the flow rate to the set flow rate.

[0098] The powder tank 1-21 is filled with dry powder fire extinguishing agent or ultra-fine dry powder fire extinguishing agent or a mixture thereof through a powder filling port 1-24;

[0099] The dry powder fire extinguishing agent or ultra-fine dry powder fire extinguishing agent adopts BC type or ABC type dry powder fire extinguishing agent or ultra-fine dry powder fire extinguishing agent;

[0100] The compressed air foam-powder combined device 1 can adopt a fixed compressed air foam-powder combined module or a mobile compressed air foam-powder combined fire fighting vehicle;

[0101] The fire extinguishing agent release device 4 is configured as more than one equal-length arc tube with a tube diameter of 10 mm to 200 mm. A plurality of release holes are evenly opened or a plurality of nozzles are installed on each arc tube. The flow diameter of the release holes or nozzles is 2 mm to 40 mm. The release holes or nozzles are spaced 100 mm to 2000 mm apart. The arc tubes are spaced 100 mm to 500 mm apart. The device is made of high-temperature resistant metal material.

[0102] The fire extinguishing agent release device 4 is installed on the inner wall of the tank top or on the floating plate of the oil tank 5, and can evenly spray compressed air foam or powdered fire extinguishing agent;

[0103] A partition valve 2 is provided on the fire extinguishing agent delivery pipeline 3 connecting the fire extinguishing agent release device 4 and the fire extinguishing agent output port 1-25. The partition valve 2 is used to control the connected fire extinguishing agent release device 4 to release the fire extinguishing agent.

[0104] The fire extinguishing agent release device 4 adopts a compressed air foam release device 6 and a powder release device 7.

[0105] The compressed air foam release device 6 adopts a compressed air foam cannon or a foam gun.

[0106] The powder releasing device 7 is a powder fire monitor or a powder fire gun.

[0107] The fire extinguishing agent outlet 1-25 is connected to the compressed air foam release device 6 through the foam pipe 3-1;

[0108] The powder output port 1-26 is connected to the powder release device 7 through the dry powder tube 3-2;

[0109] A foam control valve 2-1 is provided on the foam pipe 3-1;

[0110] A powder control valve 2-2 is provided on the dry powder tube 3-2.

[0111] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for extinguishing a low-boiling-point flammable liquid storage tank, characterized in that: Steps include; S1. Fire control and cooling: For fires in low-boiling-point flammable liquid storage tanks, high-stability compressed air foam is applied to quickly control the low-boiling-point flammable liquid fire, and a foam blanket is formed on the surface of the low-boiling-point flammable liquid to gradually cool the liquid until it drops below the boiling point of the low-boiling-point flammable liquid, and only the residual flame of oil vapor remains on the surface of the foam blanket; S2. Extinguish open flames: For the residual flames of low-boiling-point flammable liquid oil vapor on the surface of the foam blanket, quickly spray and release dry powder fire extinguishing agent, and use the excellent chemical suppression and fire extinguishing performance of dry powder fire extinguishing agent to completely extinguish the residual flames of oil vapor on the surface of the foam blanket; S3. Anti-reignition protection: After the fire in the low-boiling-point flammable liquid storage tank is completely extinguished, continue to apply high-stability compressed air foam to form a foam blanket on the surface of the low-boiling-point flammable liquid to continuously cool it down and effectively prevent it from re-igniting.

2. The method for extinguishing a low-boiling-point flammable liquid storage tank according to claim 1, characterized in that: The foaming multiple of the high-stability compressed air foam in steps S1 and S3 is greater than or equal to 4 times, the 25% liquid separation time is greater than or equal to 3 minutes, and the foam supply intensity is 5L / (min·m 2 )~30L / (min·m 2 ); The thickness of the foam blanket in step S1 is 100-200 mm, and the foaming time is 1 min to 10 min; The dry powder fire extinguishing agent in step S2 is an oil-water dual-repellent dry powder or an ultra-fine dry powder, and the effective injection rate of a single injection device is 1kg / s~30kg / s, and the injection time is 10s~120s; In step S3, the time for continuously applying the highly stable compressed air foam is 1 min to 30 min; and the thickness of the foam blanket is 300-1000 mm.

3. A low boiling point flammable liquid storage tank fire extinguishing system, characterized in that: include, Compressed air foam-powder combined device, fire extinguishing agent delivery pipeline, fire extinguishing agent release device, system controller; The compressed air foam and powder fire extinguishing agent generated by the compressed air foam-powder combination device are transported to the fire extinguishing agent release device through the fire extinguishing agent delivery pipeline, and are sprayed through the fire extinguishing agent release device; the system controller controls which fire extinguishing medium the compressed air foam-powder combination device uses and whether to open the fire extinguishing agent release device; The compressed air foam-powder combined device adopts a centralized supply type device or an independent supply type device; The centralized supply device can generate compressed air foam and powder fire extinguishing agent in stages, and output the compressed air foam and powder fire extinguishing agent in sequence through the common fire extinguishing agent delivery pipeline and output port; The independent supply type device can simultaneously generate and output compressed air foam and powder through independent conveying pipelines and output ports, and spray them through the compressed air foam release device and the powder release device respectively.

4. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 3 is characterized in that: The compressed air foam-powder combined device uses a common air source to produce the highly stable compressed air foam and powder fire extinguishing agent. The combined device produces and outputs highly stable compressed air foam and powder fire extinguishing agent. The highly stable compressed air foam and powder fire extinguishing agent are transported through the same or different transport pipelines and are sprayed through the same or different release devices.

5. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 4, characterized in that: The compressed air foam-powder combined device comprises an air source, a foam generating device, a dry powder supply source and a fire extinguishing agent output port; The foam generating device comprises a fire water tank and a fire pump connected to the fire water tank, and a water supply valve is arranged between the fire water tank and the fire pump; The foam generating device also includes a foam liquid tank, which is connected to a liquid supply valve, a foam liquid pump and a foam liquid flow meter in sequence through a pipeline. The output ends of the fire pump and the foam liquid flowmeter are both connected to the foam mixed liquid flowmeter, one end of the foam mixed liquid flowmeter is connected to a liquid regulating valve, the liquid regulating valve is connected to one inlet of the gas-liquid mixer, and the other inlet is connected to the gas source, and a gas flowmeter and a gas flow regulating valve are also provided on the pipeline connecting the gas-liquid mixer and the gas source; The outlet of the gas-liquid mixer is connected to the fire extinguishing agent outlet; The dry powder supply source is mainly a powder tank, a powder inlet is arranged in the powder tank, the powder inlet is connected to the powder outlet through a pipeline, and a powder outlet valve is arranged on the pipeline connected to the powder inlet; An air inlet is provided at the bottom of the powder tank; the air inlet is connected to an air source, and an air inlet valve is provided between the air inlet and the air source; The fire water tank is provided with a water supply valve; The foam liquid tank is provided with a liquid replenishing valve; The powder tank is provided with a powder filling port.

6. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 5, characterized in that: When foam and dry powder are used sequentially, the output port of the dry powder supply source may also be shared with the fire extinguishing agent output port of the foam generating device.

7. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 6, characterized in that: The gas source includes an air compressor and a buffer gas tank connected to the output end of the air compressor. A one-way valve is connected to the output end of the buffer gas tank, and the one-way valve can prevent the fire extinguishing agent from spraying back into the buffer gas tank and the air compressor.

8. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 7, characterized in that: The compressed air foam-powder combination device is also provided with a central controller connected to an air inlet valve and a powder output valve to control the output of the split body; It is connected with a foam liquid pump, a liquid regulating valve and a gas flow regulating valve to control the flow of the foam liquid; It is connected with a foam mixed liquid flow meter, a foam liquid flow meter and a gas flow meter to monitor and assist in controlling and regulating the stable generation of foam; The central controller adaptively adjusts the flow rate to the set flow rate.

9. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 6, characterized in that: The fire extinguishing agent release device is configured as more than one arc-shaped tube with a tube diameter of 10 mm to 200 mm. A plurality of release holes are evenly opened or a plurality of nozzles are installed on each arc-shaped tube. The flow diameter of the release holes or nozzles is 2 mm to 40 mm. The release holes or nozzles are spaced 100 mm to 2000 mm apart. The arc-shaped tubes are spaced 100 mm to 500 mm apart. The device is made of high temperature resistant metal material. The fire extinguishing agent release device is installed on the inner wall of the oil tank top or on the floating plate, and can evenly spray compressed air foam or powder fire extinguishing agent; A partition valve is provided on the fire extinguishing agent delivery pipeline connecting the fire extinguishing agent release device and the fire extinguishing agent output port, and the partition valve is used to control the connected fire extinguishing agent release device to release the fire extinguishing agent.

10. The low boiling point flammable liquid storage tank fire extinguishing system according to claim 5, characterized in that: The fire extinguishing agent release device adopts a compressed air foam release device and a powder release device respectively; The compressed air foam releasing device adopts a compressed air foam cannon or a foam gun; The powder release device adopts a powder fire monitor or a powder fire gun; The fire extinguishing agent outlet is connected to a compressed air foam release device through a foam pipe; The powder output port is connected to the powder release device through a dry powder tube; A foam control valve is provided on the foam pipe; A powder control valve is provided on the dry powder tube.

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