Disaster prevention facility, fuel cell vehicle equipped with disaster prevention facility, hydrogen trailer, and stationary facility

Abstract

To provide disaster prevention equipment capable of preventing re-blocking of a fusible plug type safety valve and visualizing a jet flame of hydrogen discharged into the atmosphere.SOLUTION: Disaster prevention equipment 1 for cooling a hydrogen storage vessel 100 on which a fusible plug type relief valve 102 is mounted in the event of a fire includes a cooling water 11a for cooling the hydrogen storage vessel 100, first piping 15 for supplying the cooling water 11a, and a nozzle 14 communicating with the first piping 15 and capable of injecting the cooling water 11a toward the hydrogen storage vessel 100, and is configured such that the fusible plug type relief valve 102 is not covered with water by the cooling water 11a injected from the nozzle 14 to the hydrogen storage vessel 100.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to disaster prevention equipment for cooling a hydrogen storage container equipped with a fusible plug type safety valve in the event of a fire, and to a fuel cell vehicle, a hydrogen trailer, and a stationary facility equipped with this disaster prevention equipment. [Background technology]

[0002] Currently, "hydrogen" is becoming popular as one of the next-generation energy sources. Hydrogen has the characteristic that it does not emit CO2 when used as an energy source. For example, hydrogen is produced at hydrogen production plants. The hydrogen produced at the hydrogen production plants is transported by hydrogen trailers and stored at hydrogen stations. The hydrogen stored at hydrogen stations is provided to fuel cell vehicles such as passenger cars, motorcycles, buses, and trucks, and is used to generate electricity in the fuel cells.

[0003] Hydrogen for sale to hydrogen stations and fuel cell vehicles is generally stored and transported in the form of compressed hydrogen filled in composite containers. Hydrogen for industrial use is also stored and transported in the form of liquefied hydrogen cooled to -253°C. Furthermore, storage and transport of hydrogen in the form of organic hydrides (e.g., MCH: methylcyclohexane) obtained by combining hydrogen with organic substances such as toluene is now at the practical stage. Other methods being considered include storing and transporting hydrogen as ammonia (NH3), and storing and transporting hydrogen atoms by absorbing them into alloys.

[0004] The composite container filled with compressed hydrogen is constructed with an aluminum liner covered with carbon fiber reinforced plastic. If a composite container filled with compressed hydrogen encounters a fire, the heat of the fire will increase the internal pressure, posing a risk of the composite container bursting. For this reason, conventional composite containers are equipped with a fusible plug-type safety valve that automatically releases the hydrogen inside the container when it becomes hot.

[0005] For example, Figure 4 of Japanese Patent Application Laid-Open No. 2015-230071 discloses a hydrogen trailer 1 equipped with a plurality of high-pressure hydrogen containers A each equipped with a fusible plug type safety valve Ab. As shown in Figures 6 to 8 of Japanese Patent Application Laid-Open No. 2015-230071, the fusible plug type safety valve Ab of each high-pressure hydrogen container A is connected to a release pipe 80. When the fusible plug type safety valve Ab melts due to high temperatures during a fire, the hydrogen inside the high-pressure hydrogen container A is released from the release pipe 80 into the atmosphere.

[0006] 1 and 2 of JP 2017-038789 A disclose a hydrogen station equipped with a first supply line 25 that supplies water for extinguishing a fire and a second supply line 26 that supplies a smaller amount of water than the first supply line 25. When an abnormality such as a fire is detected, a sufficient amount of water for extinguishing the fire is supplied from the first supply line 25 to the water spray head 24. On the other hand, when the surface temperature of the storage tank 13 rises, a small amount of water for cooling is supplied from the second supply line 26 to the water spray head 24.

[0007] Figure 1 of Japanese Patent Application Laid-Open No. 2006-271900 discloses a hydrogen station that is configured to release mist from multiple mist nozzles 6 to increase humidity within a protected area when a hydrogen leak is detected from a hydrogen storage tank 2 and a hydrogen dispenser 3. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-230071 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-038789 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-271900 Summary of the Invention [Problem to be solved by the invention]

[0009] The operating temperature of the fusible plug safety valve installed in the composite vessel is generally set to approximately 110°C. In the case of a composite vessel for a fuel cell vehicle (e.g., internal pressure 15 MPa, volume 47 L), the hydrogen in the vessel is released into the atmosphere approximately one minute after the fusible plug safety valve is activated. However, if a fusible plug safety valve is exposed to coolant or fire extinguishing agent, the metal of the fusible plug resolidifies, re-blocking the hydrogen release path. This delays the release of hydrogen from the vessel into the atmosphere in the event of a fire, potentially leading to the composite vessel rupture. If the composite vessel ruptures, burning fragments of the vessel will fly and cause significant damage to the surrounding area. Therefore, rupture of the composite vessel must be avoided at all costs. Therefore, it is important to release all hydrogen in the vessel into the atmosphere as quickly as possible after a fire breaks out and empty the composite vessel.

[0010] Meanwhile, the hydrogen inside the vessel passes through the fusible plug safety valve and the hydrogen release pipe, and is released into the atmosphere from the outlet of the hydrogen release pipe at high pressure. If the hydrogen released from the outlet of the hydrogen release pipe ignites, a hydrogen jet flame will form. Because a hydrogen jet flame released at high pressure is difficult to extinguish, the basic response measure is to continue burning the hydrogen while monitoring it to prevent the fire from spreading. However, because the color of the flame when hydrogen burns is nearly colorless and transparent, it is difficult to see the hydrogen jet flame with the naked eye.

[0011] The present invention has been made in consideration of the above problems, and aims to provide disaster prevention equipment that can prevent the refouling of a fusible plug type safety valve and that can visualize the jet flame of hydrogen released into the atmosphere, as well as a fuel cell vehicle, a hydrogen trailer, and a stationary facility that are equipped with this disaster prevention equipment. [Means for solving the problem]

[0012] (1) In order to achieve the above-mentioned object, the disaster prevention equipment of the present invention is a disaster prevention equipment for cooling a hydrogen storage container equipped with a fusible plug type safety valve in the event of a fire, and is characterized by comprising cooling water for cooling the hydrogen storage container, a first pipe for supplying the cooling water, and a nozzle connected to the first pipe and capable of spraying the cooling water toward the hydrogen storage container, and is configured so that the fusible plug type safety valve is not wetted by the cooling water sprayed from the nozzle toward the hydrogen storage container.

[0013] (2) Preferably, in the disaster prevention equipment of (1) above, the nozzle is installed at a position where the fusible plug type safety valve is not submerged in the cooling water sprayed from the nozzle into the hydrogen storage container.

[0014] (3) Preferably, in the disaster prevention equipment of (1) or (2) above, the nozzle is installed in a direction such that the fusible plug type safety valve is not submerged in the cooling water sprayed from the nozzle into the hydrogen storage container.

[0015] (4) Preferably, in the disaster prevention equipment of any of (1) to (3) above, the injection pattern of the cooling water injected from the nozzle into the hydrogen storage container is an injection pattern that prevents the fusible plug type safety valve from becoming wet.

[0016] (5) Preferably, in any of the disaster prevention equipment described above in (1) to (4), a shielding plate is provided to block the cooling water from scattering and / or flowing in the direction of the fusible plug type safety valve, thereby preventing the fusible plug type safety valve from being submerged in water.

[0017] (6) Preferably, in any of the disaster prevention equipment described above in (1) to (5), a substance that gives the cooling water thickening or gelling properties is added to increase the viscosity of the cooling water attached to the surface of the hydrogen storage container, thereby preventing the fusible plug type safety valve from becoming wet.

[0018] (7) Preferably, in the disaster prevention equipment of (6) above, the substance that gives the cooling water thickening or gelling properties is a substance having thixotropy.

[0019] (8) Preferably, in any of the disaster prevention equipment described in (1) to (5) above, a substance that imparts wettability to the cooling water is added to reduce the surface tension of the cooling water relative to the surface of the hydrogen storage container, thereby preventing the fusible plug type safety valve from becoming wet.

[0020] (9) Preferably, in the disaster prevention system of (8) above, the substance that imparts wettability to the cooling water is a surfactant.

[0021] (10) Preferably, in any of the disaster prevention equipment described above in (1) to (9), a substance that produces a flame color reaction is mixed with the hydrogen released from the hydrogen storage container via the fusible plug type safety valve.

[0022] (11) Preferably, in the disaster prevention equipment of (10) above, a second pipe is provided which is connected to the outlet of the fusible plug type safety valve, and the substance which causes the flame color reaction is injected near the outlet of the second pipe, thereby mixing the substance which causes the flame color reaction with the hydrogen released from the hydrogen storage container.

[0023] (12) Preferably, in the disaster prevention equipment of (10) or (11) above, the substance that causes a flame color reaction is an aqueous sodium chloride solution.

[0024] (13) Preferably, the disaster prevention equipment of (1) to (12) above includes a fire detector installed in the same location as the hydrogen storage container, and a control unit that starts the supply of the cooling water based on a signal from the fire detector.

[0025] (14) In order to achieve the above object, the fuel cell vehicle of the present invention is a fuel cell vehicle equipped with at least one hydrogen storage container fitted with a fusible plug type safety valve, and is characterized by being equipped with any of the disaster prevention equipment described above in (1) to (13).

[0026] (15) In order to achieve the above object, the hydrogen trailer of the present invention is a hydrogen trailer having a loading platform on which a plurality of hydrogen storage containers equipped with fusible plug type safety valves are loaded, and is characterized by being equipped with any of the disaster prevention equipment described above in (1) to (13).

[0027] (16) In order to achieve the above object, the stationary equipment of the present invention is a stationary equipment having at least one hydrogen storage container equipped with a fusible plug type safety valve, and is characterized by being equipped with any one of the disaster prevention equipments (1) to (13) above. [Effects of the Invention]

[0028] The disaster prevention equipment of the present invention, and the fuel cell vehicle, hydrogen trailer, and stationary facility equipped with this disaster prevention equipment, can prevent the fusible plug-type safety valve from closing again and make it possible to visualize the jet flame of hydrogen released into the atmosphere, thereby preventing the hydrogen storage container from exploding in the event of a fire and preventing the spread of the fire by visually monitoring the hydrogen jet flame. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a schematic diagram showing disaster prevention equipment according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing a disaster prevention system according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing a disaster prevention system according to a third embodiment of the present invention. [Figure 4] Fig. 4(a) is a front view of a nozzle constituting the disaster prevention equipment according to the first embodiment. Fig. 4(b) is a side view of the nozzle. Fig. 4(c) is a bottom view of the nozzle. Fig. 4(d) is a partially enlarged view showing the spray angle and spray pattern of the nozzle. Fig. 4(e) is a partially enlarged cross-sectional view showing the vicinity of the outlet of the hydrogen release pipe constituting the disaster prevention equipment according to the first embodiment. Fig. 4(f) is a partially enlarged cross-sectional view showing the vicinity of the outlet of the hydrogen release pipe constituting the disaster prevention equipment according to the second and third embodiments. [Figure 5]5(a) to 5(c) are schematic diagrams showing a shielding plate for preventing the fusible plug type safety valve from being wetted. [Figure 6] Figure 6(a) is a schematic diagram showing a fuel cell vehicle according to an embodiment of the present invention, Figure 6(b) is a schematic diagram showing a hydrogen trailer according to an embodiment of the present invention, and Figure 6(c) is a schematic diagram showing a stationary facility according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, disaster prevention equipment according to embodiments of the present invention, a fuel cell vehicle equipped with this disaster prevention equipment, a hydrogen trailer, and a stationary equipment will be described with reference to the drawings.

[0031] 1. First embodiment of disaster prevention equipment FIG. 1 shows a disaster prevention system 1 according to a first embodiment of the present invention. The disaster prevention system 1 is used to cool a hydrogen storage container 100 in the event of a fire, and is installed in, for example, a fuel cell vehicle 2, a hydrogen trailer 3, or a stationary facility 4 such as a hydrogen station or hydrogen production plant, as shown in FIGS. 6(a) to 6(c). The hydrogen storage container 100 is equipped with a fusible plug-type safety valve 102 for releasing hydrogen from the container in the event of a fire. The purpose of the disaster prevention system 1 is to prevent the hydrogen storage container 100 from rupturing in the event of a fire, and / or to visualize the jet flame of hydrogen released into the atmosphere.

[0032] As shown in Fig. 1, the disaster prevention equipment 1 is mainly composed of a first group of mechanical elements for preventing the rupture of the hydrogen storage container 100 and a second group of mechanical elements for visualizing the hydrogen jet flame. To facilitate understanding, the first and second groups of mechanical elements are conceptually divided into upper and lower sections in Fig. 1, with the dashed dotted line as the boundary. However, the fire alarm 30 and the control unit 40 perform control processing for both the first and second groups of mechanical elements.

[0033] 1-1. Structure to prevent hydrogen storage container from exploding As shown below the dashed line in FIG. 1 , a first group of mechanical elements includes a cooling water tank 11, a pump 12, a first motor-operated valve 13, a first nozzle 14, and a first pipe 15. The cooling water tank 11 stores cooling water 11a for cooling the hydrogen storage container 100 in the event of a fire. The inlet of the pump 12 is connected to the outlet of the cooling water tank 11 via the first pipe 15. The outlet of the pump 12 is connected to the inlet of the first motor-operated valve 13 via the first pipe 15. The outlet of the first motor-operated valve 13 is connected to the inlet of the first nozzle 14 via the first pipe 15. The pump 12 and the first motor-operated valve 13 are electrically connected to a control unit 40, and their operations are controlled by the control unit 40. A fire detector 30 is installed in the protected area where the hydrogen storage container 100 is installed.

[0034] The fire detector 30 detects, for example, at least one of heat, flame, and smoke, and outputs a signal to the control unit 40. Based on the signal from the fire detector 30, the control unit 40 operates the pump 12 and opens the first electric valve 13. As a result, cooling water 11a stored in the cooling water tank 11 is sucked into the pump 12 and sprayed from the first nozzle 14 into the hydrogen storage container 100 via the first piping 15. The cooling water 11a sprayed from the first nozzle 14 cools the hydrogen storage container 100 in the event of a fire, and prevents the hydrogen storage container 100 from bursting due to overheating.

[0035] 1-1-1.Configuration to prevent water from entering the fusible plug type safety valve Simply cooling the hydrogen storage container 100 with cooling water 11a is not enough to prevent the hydrogen storage container 100 from bursting. To prevent the hydrogen storage container 100 from bursting, it is necessary to empty the hydrogen storage container 100 by releasing all of the hydrogen in the hydrogen storage container 100 into the atmosphere as soon as possible after a fire breaks out. As shown in FIG. 1 , the hydrogen in the hydrogen storage container 100 is released when the fusible plug of the fusible plug safety valve 102 melts due to the heat of the fire. However, if the fusible plug safety valve 102 is exposed to water by the cooling water 11a sprayed from the first nozzle 14, the melted fusible plug may be cooled, causing the outlet of the fusible plug safety valve 102 to close again. For this reason, the disaster prevention device 1 of this embodiment is provided with the following configuration to prevent the fusible plug safety valve 102 from being exposed to water.

[0036] 1-1-2. Nozzle No. 1 The first nozzle 14 is installed in a position and orientation that prevents the fusible plug type safety valve 102 from being wetted by the cooling water 11a sprayed into the hydrogen storage container 100. As shown in Figure 1, the first nozzle 14 is installed in the center of the hydrogen storage container 100 away from the fusible plug type safety valve 102, and is oriented so that the cooling water 11a is sprayed toward the center of the hydrogen storage container 100.

[0037] The first nozzle 14 is configured so that the cooling water 11a injected toward the center of the hydrogen storage container 100 is sprayed at an injection angle and in an injection pattern that prevents the fusible plug type safety valve 102 from being wetted. As shown in FIGS. 4(a) to 4(c), the tip of the first nozzle 14 is provided with a tip 14a having an injection port formed therein and a retainer 14b for holding the tip 14a. The injection angle and injection pattern of the first nozzle 14 can be adjusted by the configuration of the tip 14a and the retainer 14b. The tip 14a is formed with a substantially elliptical injection port and a groove extending laterally that surrounds the injection port. Meanwhile, the retainer 14b is formed with a pair of cutouts with an inverted U-shaped cross section that correspond to both ends of the groove extending laterally in the tip 14a. The injection angle and injection pattern of the first nozzle 14 are determined by the dimensions of the injection port, groove, and cutouts. 4(d), the spray angle of the first nozzle 14 is set within a range of, for example, 15° to 115°. The spray pattern of the first nozzle 14 is set to be a sector (see FIG. 1) that exhibits a uniform flow rate distribution over almost the entire area.

[0038] 1-1-3. Cooling water The cooling water 11a sprayed from the first nozzle 14 contains additives that affect its physical properties. For example, the cooling water 11a may contain substances that thicken or gel the cooling water 11a, such as sodium alginate, cellulose, gum arabic, pectin, gelatin, or polyethylene glycol; minerals containing colloidal hydrous silicate, such as smectite, bentonite, or montmorillonite; synthetic inorganic polymer compounds composed of colloidal hydrous silicate; or thickening polysaccharides, such as xanthan gum or guar gum, to improve adhesion to the hydrogen storage container 100. Adding a substance that imparts thixotropy, among other substances that impart thickening or gelling properties, can improve the cooling water 11a's viscosity by decreasing when subjected to shear stress and increasing when not subjected to shear stress. This thixotropy reduces the viscosity of the cooling water 11a when sprayed from the first nozzle 14. Thereafter, the viscosity of the cooling water 11a adhering to the surface of the hydrogen storage container 100 increases, and the fusible plug type safety valve 102 becomes less susceptible to water damage.

[0039] The substance that imparts thixotropy to the cooling water 11a is not particularly limited, and examples thereof include minerals containing colloidal hydrous silicate, such as smectite, bentonite, and montmorillonite; synthetic inorganic polymer compounds made of colloidal hydrous silicate; and thickening polysaccharides, such as xanthan gum and guar gum. It is more preferable to use thickening polysaccharides, such as xanthan gum and guar gum, because these thickening polysaccharides are used in food products and are harmless to humans and animals.

[0040] Alternatively, for example, a substance that imparts wettability to the cooling water 11a may be added to reduce the surface tension of the cooling water 11a adhering to the surface of the hydrogen storage container 100, thereby preventing the fusible plug type safety valve 102 from becoming wet. Examples of substances that impart wettability include surfactants, organic solvents, alcohols, polymeric compounds, fatty acids, oils and fats, and dispersants, with surfactants being particularly preferred. Adding a surfactant reduces the contact angle between the cooling water 11a and the contact surface, making it easier for the cooling water 11a to adhere to the surface of the hydrogen storage container 100. Reducing the surface tension of the cooling water 11a in this way makes it less likely for the fusible plug type safety valve 102 to become wet.

[0041] The surfactant is not particularly limited, but from the viewpoint of suppressing adverse effects on the environment, hydrocarbon surfactants are preferred. Hydrocarbon surfactants have a hydrophobic group consisting of carbon and hydrogen. Examples of hydrocarbon surfactants include hydrocarbon nonionic surfactants, hydrocarbon cationic surfactants, hydrocarbon anionic surfactants, and hydrocarbon amphoteric surfactants, and from the viewpoint of wettability, hydrocarbon nonionic surfactants are preferred. From the viewpoint of wettability, hydrocarbon nonionic surfactants are preferably those having an HLB value of 3 to 20, as determined by the Griffin method, and more preferably those having an HLB value of 8 to 16.

[0042] Here, HLB is an acronym for Hydrophilic-Lipophilic Balance, and is a value that represents the degree of affinity of a surfactant for water and oil (a water-insoluble organic compound). HLB takes values ​​from 0 to 20, with the closer to 0 the higher the lipophilicity and the closer to 20 the higher the hydrophilicity. There are known methods for determining HLB by calculation (such as the Atlas method, Griffin method, Davis method, and Kawakami method), but the HLB in this specification is the value determined by the Griffin method.

[0043] When two or more surfactants are used, the HLB is the weighted average of the HLB values ​​of each component, and when two types of surfactants are used, it is expressed by the following formula: HLB=N 1 HLB ×W 1 +N 2 HLB ×W 2 where N 1 HLB· N 2 HLB : HLB of each surfactant W 1 ·W 2 : Weight fraction of each surfactant (W 1 +W 2 =1) Below, the HLB can be calculated using the same method when there are three or more types of surfactants.

[0044] Examples of hydrocarbon-based nonionic surfactants include polyoxyethylene alkyl ether type, polyoxyethylene alkylphenol type, polyoxyethylene alkylamine type, polyoxyethylene alkylamide type, polyoxyethylene fatty acid ester type, propylene glycol fatty acid ester type, propylene glycol fatty acid dipolyoxyethylene lanolin ether type, aliphatic alkanolamide type, polyoxyethylene castor oil type, polyoxyethylene polyhydric alcohol type, polyhydric alcohol fatty acid ester type, and polyoxyethylene polyhydric alcohol fatty acid ester type nonionic surfactants, and more specific examples include polyoxyethylene oleyl ether, polyoxyethylene decyl ether, polyoxyethylene tridecyl ether, polyoxyethylene 2-ethylhexyl ether, polyoxyethylene lauryl ether, sorbitan tristearate, and polyoxyethylene castor oil. These are commercially available, for example, as Rheodor SP-S30V from Kao Corporation, BR-404, EN-1502, and EN-1504 from the Brownon series, and D-1303 and TD-50 from the Finesurf series from Aoki Oil & Fat Co., Ltd. The hydrocarbon nonionic surfactants may be used alone or in combination of two or more.

[0045] Examples of hydrocarbon cationic surfactants include monoalkylammonium chloride, dialkylammonium chloride, EO-added ammonium chloride, tetramethylammonium chloride, benzyltrimethylammonium chloride, etc. The hydrocarbon cationic surfactants may be used alone or in combination of two or more.

[0046] Examples of hydrocarbon-based anionic surfactants include alkyl ether sulfates, alpha olefin sulfonates, alkyl benzene sulfonic acids and their salts, alkyl sulfates, ether sulfonates, ether carboxylates, sulfosuccinates, methyl taurates, alaninates and their salts, etc. The hydrocarbon-based anionic surfactants may be used alone or in combination of two or more.

[0047] Examples of hydrocarbon-based amphoteric surfactants include alanine-type, imidazolinium betaine-type, aminopropyl betaine-type, and aminodipropione-type amphoteric surfactants. Preferably, imidazolinium betaine-type amphoteric surfactants are used. The hydrocarbon-based amphoteric surfactants may be used alone or in combination of two or more.

[0048] The fatty acids may be either straight-chain or branched, natural or synthetic, saturated or unsaturated, and examples thereof include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, beef tallow fatty acid, oleic acid, hardened castor fatty acid, linoleic acid, palmitoleic acid, linolenic acid, etc. The fatty acids may be used singly or in combination of two or more.

[0049] Examples of organic solvents include cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, carbitols such as ethyl carbitol and butyl carbitol, and polyoxyethylene lower alkyl ethers having an added mole number of ethylene oxide of 3 to 10. The organic solvents may be used alone or in combination of two or more.

[0050] Examples of polymer compounds include cellulose derivatives such as methyl cellulose and hydroxyethyl cellulose, polyvinyl alcohol, sodium alginate, polyvinyl ether, polyethylene glycol, etc. The polymer compounds may be used singly or in combination of two or more.

[0051] Examples of dispersants include naphthalenesulfonic acid-based, alkylnaphthalenesulfonic acid-based, polycarboxylic acid-based, polystyrenesulfonic acid-based, alkylamine-based, and alkylphenol-based dispersants. The dispersants may be used singly or in combination of two or more.

[0052] Examples of alcohols include lower alcohols such as methanol and ethanol, higher alcohols such as lauryl alcohol and myristyl alcohol, and polyhydric alcohols other than glycols such as glycerin and sorbitol. The alcohols may be used alone or in combination of two or more.

[0053] The oils and fats may be either natural oils and fats or synthetic oils and fats, and examples thereof include processed oil, silicone oil, mineral oil, wax, etc. The oils and fats may be used singly or in combination of two or more.

[0054] From the viewpoint of improving the fire extinguishing ability, the cooling water 11a preferably contains a potassium salt. Potassium salts include inorganic potassium salts and organic potassium salts. Inorganic potassium salts include potassium hydroxide, potassium tetraborate, potassium nitrate, potassium carbonate, potassium sulfate, potassium phosphate, potassium hydrogen phosphate, potassium bromide, and potassium chloride. Organic potassium salts include potassium acetate, potassium stearate, potassium citrate, potassium lactate, potassium tartrate, potassium succinate, potassium malate, and potassium glycolate. Potassium salts may be used alone or in combination of two or more. Among these, organic potassium salts are preferred from the viewpoints of not violating the Industrial Safety and Health Act and minimizing environmental impact, and potassium acetate, which is also used as a pharmaceutical raw material, is more preferred.

[0055] The cooling water 11a preferably contains glycols from the viewpoint of suppressing coloration and lowering the freezing point. Preferred glycols include those having 2 to 10 carbon atoms, and specific examples include monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethyl glycol, ethyl diglycol, butyl glycol, and propylene glycol monoethyl ether. The glycols may be used alone or in combination of two or more. Among these, propylene glycol and diethylene glycol are preferred, and propylene glycol is more preferred, from the viewpoints of not violating the Industrial Safety and Health Act and suppressing environmental impact.

[0056] From the viewpoint of combustion resistance, the cooling water 11a preferably contains a phosphoric acid ester. Examples of phosphate esters include acidic phosphate esters such as monomethyl acid phosphate and butyl acid phosphate; phosphites such as diethyl phosphite; phosphate ester salts such as polyoxyethylene alkyl ether phosphate and alkyl phosphate; trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, and aliphatic phosphate amidates. Phosphate esters may be used alone or in combination of two or more. Among these, acidic phosphate esters are preferred because they do not violate the Industrial Safety and Health Act and have a high flame retardant effect in terms of reducing environmental impact.

[0057] Furthermore, by giving the cooling water 11a sprayed from the first nozzle 14 thickening, gelling, thixotropy or wettability, not only does the fusible plug type safety valve 102 become less susceptible to water damage, but a water film is formed that widely covers the surface of the hydrogen storage container 100, improving the cooling effect of the hydrogen storage container 100.

[0058] 1-2.Configuration for visualizing hydrogen jet flames As shown above the dashed line in FIG. 1 , the second group of mechanical elements includes an aqueous solution tank 21, a pressurized container 22, an initiator 22a, a second motor-operated valve 23, a second nozzle 24, and a second pipe 25. The aqueous solution tank 21 stores an aqueous solution, such as a sodium chloride aqueous solution 21a, to which a substance that causes a flame color reaction has been added. The pressurized container 22 is filled with a high-pressure gas. The high-pressure gas filled in the pressurized container 22 may be air, but is preferably an inert gas such as carbon dioxide gas, nitrogen gas, or a mixture thereof. The outlet of the pressurized container 22 is sealed with a sealing plate (not shown). An initiator 22a is attached to the outlet of the pressurized container 22. The initiator 22a is an electric ignition device that breaks the sealing plate of the pressurized container 22.

[0059] The outlet of the pressurized container 22 is connected to the aqueous solution tank 21 via the second pipe 25. The outlet of the aqueous solution tank 21 is connected to the inlet of the second electric valve 23 via the second pipe 25. The outlet of the second electric valve 23 is connected to the inlet of the second nozzle 24 via the second pipe 25. The second nozzle 24 is disposed near the outlet of the hydrogen release pipe 102a. The initiator 22a and the second electric valve 23 are electrically connected to the control unit 40, and their operations are controlled by the control unit 40.

[0060] The control unit 40 ignites the initiator 22a based on a signal from the fire detector 30, and then opens the second motor-operated valve 23. By igniting the initiator 22a, the seal of the pressurized container 22 is broken, and the high-pressure gas in the pressurized container 22 is filled into the aqueous solution tank 21. This increases the pressure in the aqueous solution tank 21, and the sodium chloride aqueous solution 21a stored in the aqueous solution tank 21 is sprayed from the second nozzle 24 through the second pipe 25 to the vicinity of the outlet of the hydrogen release pipe 102a.

[0061] 4(e), the sodium chloride aqueous solution 21a sprayed from the second nozzle 24 is mixed with the hydrogen 100a released into the atmosphere from the outlet of the hydrogen release pipe 102a. As a result, even if the hydrogen 100a released into the atmosphere from the outlet of the hydrogen release pipe 102a ignites and a jet flame of the hydrogen 100a is formed, the sodium chloride aqueous solution 21a mixed with the hydrogen 100a causes a flame color reaction, making the jet flame of the hydrogen 100a visible. Specifically, the flame color reaction of the sodium chloride aqueous solution 21a colors the jet flame of the hydrogen 100a yellow.

[0062] 1-2-1.Aqueous solution Additives to the aqueous solution for generating the flame color reaction include water-soluble metal salts and water-soluble organic metals, and are not limited to the sodium chloride aqueous solution 21a. For example, an aqueous solution containing an alkali metal other than sodium chloride (Na), an alkaline earth metal, copper (Cu), boron (B), gallium (Ga), indium (In), or thallium (Tl) may be used. Examples of alkali metals other than sodium chloride include lithium (Li), potassium (K), rubidium (Rb), and cesium (Cs). Examples of alkaline earth metals include magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). Aqueous solutions containing these substances can also generate a flame color reaction for visualizing the jet flame of hydrogen 100a.

[0063] 1-2-2.Timing of aqueous solution injection In this embodiment, the sodium chloride aqueous solution 21a is sprayed based on a signal from the fire detector 30, but the timing is not limited to this. For example, the aqueous solution for causing a flame reaction may be sprayed when the temperature within the protected area reaches the melting temperature of the fusible plug of the fusible plug type safety valve 102 (e.g., 110°C ± 10°C). In this case, a temperature sensor is installed within the protected area, and the control unit 40 is caused to start supplying the aqueous solution based on the temperature detected by the temperature sensor. Also, for example, the aqueous solution for causing a flame reaction may be sprayed based on the flow rate of hydrogen 100a flowing through the hydrogen release pipe 102a. In this case, a flow rate sensor is installed within the hydrogen release pipe 102a, and the control unit 40 is caused to start supplying the aqueous solution based on the flow rate detected by the flow rate sensor.

[0064] 1-2-3. Second nozzle 4(a) to 4(d), the second nozzle 24 is configured the same as the first nozzle 14, but is not limited to this. A nozzle having a different configuration from the first nozzle 14 may be used as long as it is possible to mix the hydrogen 100a released into the atmosphere from the outlet of the hydrogen release pipe 102a with an aqueous solution for causing a flame color reaction.

[0065] 2. Second embodiment of disaster prevention equipment FIG. 2 shows a disaster prevention system 1 according to a second embodiment of the present invention. The disaster prevention system 1 according to the second embodiment is configured to pump cooling water 11a from a water source using a pump 12. With this configuration, the cooling water tank 11 shown in FIG. 1 can be omitted. The water source can be, for example, a water tank or a natural water source such as a river, lake, or sea. Such a disaster prevention system 1 according to the second embodiment is suitable for a stationary facility 4 such as a hydrogen station or hydrogen production plant shown in FIG. 6(c).

[0066] Furthermore, the disaster prevention equipment 1 according to the second embodiment is configured such that the outlet of the aqueous solution tank 21 is connected to a Venturi tube 26 provided near the outlet of the hydrogen release pipe 102a. With this configuration, the pressurized container 22, initiator 22a, and second motor-operated valve 23 shown in FIG. 1 are omitted. The configuration of the Venturi tube 26 is shown in FIG. 4(f). A throttle section 26b with a small cross-sectional area is formed midway through the main pipe 26a of the Venturi tube 26. A secondary pipe 26c is connected to the throttle section 26b. The outlet of the aqueous solution tank 21 shown in FIG. 2 is connected to the secondary pipe 26c of the Venturi tube 26 via the second pipe 25.

[0067] The hydrogen 100a released from the fusible plug safety valve 102 flows through the hydrogen release pipe 102a and into the main pipe 26a of the Venturi tube 26. The flow rate of the hydrogen 100a increases as it passes through the throttle section 26b, lowering the pressure at the throttle section 26b. As a result, the sodium chloride aqueous solution 21a in the aqueous solution tank 21 is drawn from the secondary pipe 26c toward the throttle section 26b and mixed with the hydrogen 100a flowing through the main pipe 26a. This configuration using the Venturi tube 26 makes it possible to mix an appropriate amount of sodium chloride aqueous solution 21a according to the flow rate per unit time of the hydrogen 100a flowing through the main pipe 26a, without the need for control processing by the fire detector 30 and control unit 40 shown in FIG. 1.

[0068] 3. Third embodiment of disaster prevention equipment Figure 3 shows a disaster prevention system 1 according to a third embodiment of the present invention. The disaster prevention system 1 according to the third embodiment is configured to inject a fire extinguishing agent 19a into a hydrogen storage container 100 instead of the cooling water 11a shown in Figures 1 and 2. The fire extinguishing agent 19a cools the hydrogen storage container 100 in the event of a fire and also serves to extinguish any flames near the hydrogen storage container 100.

[0069] The disaster prevention equipment 1 according to the third embodiment is configured to include an extinguishing agent concentrate 17, a mixer 18, and an extinguishing agent tank 19. Other configurations are the same as those of the disaster prevention equipment 1 according to the second embodiment shown in Fig. 2. The mixer 18 mixes water pumped from a water source with the extinguishing agent concentrate 17 to generate an extinguishing agent 19a. The extinguishing agent 19a generated by the mixer 18 is stored in the extinguishing agent tank 19a.

[0070] Fire extinguishing agent 19a stored in fire extinguishing agent tank 19 is sucked into pump 12 and sprayed from first nozzle 14 through first piping 15 into hydrogen storage container 100. Fire extinguishing agent 19a sprayed from first nozzle 14 cools hydrogen storage container 100 in the event of a fire, preventing hydrogen storage container 100 from bursting due to overheating. Fire extinguishing agent 19a also extinguishes any flames near hydrogen storage container 100, preventing the hydrogen storage container 100 from catching fire.

[0071] 4. Option to prevent water from entering the fusible plug type safety valve As an option for preventing the fusible plug type safety valve 102 from being flooded in the event of a fire, shielding plates 51-52 as shown in Figures 5(a)-(c) may be attached to the hydrogen storage container 100. The shielding plates 51-52 block the cooling water 11a that splashes and / or flows toward the fusible plug type safety valve 102. This makes it possible to prevent the fusible plug type safety valve 102 from being flooded by the cooling water 11a (or the fire extinguishing agent 19a in Figure 3).

[0072] 5(a) is a compact umbrella having an area that covers the upper part of the fusible plug type safety valve 102. The umbrella-shaped shielding plate 51 can block the cooling water 11a that splashes and / or flows from above the fusible plug type safety valve 102.

[0073] 5(b) is a semi-cylindrical cover having a cross-sectional area equal to half that of the hydrogen storage container 100. The semi-cylindrical cover-type shielding plate 52 can block the cooling water 11a splashing and / or flowing from above and beside the fusible plug type safety valve 102.

[0074] 5(c) is a vertical wall having a notch formed therein that is equal to half the cross-sectional area of ​​the hydrogen storage container 100. The vertical wall-type shielding plate 53 can block the cooling water 11a that splashes and / or flows from above and to the sides of the fusible plug type safety valve 102.

[0075] 5. Use of disaster prevention equipment The disaster prevention equipment 1 of this embodiment shown in Figures 1 to 3 can be applied to, for example, a fuel cell vehicle 2, a hydrogen trailer 3, and stationary equipment 4 such as a hydrogen station or a hydrogen production plant as shown in Figures 6(a) to (c).

[0076] 5-1. Fuel cell vehicles Fig. 6(a) shows a fuel cell vehicle 2 equipped with the disaster prevention equipment 1 of Fig. 1. Note that in Fig. 6(a), the pump 12, the first electric valve 13, the pressurized container 22, the initiator 22a, the second electric valve 23, and the control unit 40 that constitute the disaster prevention equipment 1 of Fig. 1 are omitted from the illustration.

[0077] The fuel cell vehicle 2 is equipped with two hydrogen storage containers 100. Each of the two hydrogen storage containers 100 is provided with a main valve 101 (see FIG. 1) and a fusible plug type safety valve 102. The outlets of the two fusible plug type safety valves 102 are connected to one hydrogen release pipe 102a. The outlet of this hydrogen release pipe 102a passes through the ceiling of the fuel cell vehicle 2 and is located outside the vehicle. The main valve 101 of the hydrogen storage container 100 shown in FIG. 1 is connected to a fuel cell (not shown) of the fuel cell vehicle 2 via a hydrogen supply pipe 101a.

[0078] A cooling water tank 11 and an aqueous solution tank 21 are disposed below the two hydrogen storage containers 100. The outlet of the cooling water tank 11 is connected to a first pipe 15. Although not shown, a pump 12 and a first electric valve 13 are connected midway through the first pipe 15 (see FIG. 1).

[0079] Two first nozzles 14 connected to the first pipe 15 are disposed above the two hydrogen storage containers 100. Meanwhile, the outlet of the aqueous solution tank 21 is connected to one second pipe 25. Although not shown, an initiator 22a provided at the outlet of the pressurized container 22 is connected to the aqueous solution tank 21, and a second motor-operated valve 23 is connected midway through the second pipe 25 (see FIG. 1). A second nozzle 24 is connected to the outlet of the second pipe 25. The second nozzle 24 passes through the ceiling of the fuel cell vehicle 2 and is disposed near the outlet of the hydrogen release pipe 102a. Furthermore, a fire detector 30 is installed above the two hydrogen storage containers 100.

[0080] A fire that breaks out in the fuel cell vehicle 2 is detected by the fire detector 30. Based on a signal from the fire detector 30, the control unit 40 starts supplying the cooling water 11a from the cooling water tank 11. As a result, the cooling water 11a is sprayed from the two first nozzles 14 to the two hydrogen storage containers 100 via the first piping 15. The cooling water 11a sprayed from each first nozzle 14 cools each hydrogen storage container 100, preventing each hydrogen storage container 100 from bursting due to overheating.

[0081] Meanwhile, the control unit 40 starts the supply of the sodium chloride aqueous solution 21a in the aqueous solution tank 21 based on a signal from the fire detector 30. As a result, the sodium chloride aqueous solution 21a is sprayed from the second nozzle 24 through the second pipe 25 toward the vicinity of the outlet of the hydrogen release pipe 102a. The sodium chloride aqueous solution 21a is mixed with the hydrogen 100a released from the outlet of the hydrogen release pipe 102a. As a result, even if the hydrogen 100a released into the atmosphere from the outlet of the hydrogen release pipe 102a ignites and a jet flame of the hydrogen 100a is formed, the sodium chloride aqueous solution 21a mixed with the hydrogen 100a will cause a flame color reaction, making the jet flame of the hydrogen 100a visible.

[0082] 5-2. Hydrogen trailer Figure 6(b) shows a hydrogen trailer 3 equipped with the disaster prevention equipment 1 of Figure 1. Note that in Figure 6(b), the pump 12, first electric valve 13, pressurized container 22, initiator 22a, second electric valve 23, and control unit 40 that constitute the disaster prevention equipment 1 of Figure 1 are omitted from the illustration.

[0083] As shown in Figure 6(b), the configuration of the disaster prevention equipment 1 installed in the hydrogen trailer 3 is the same as that of the fuel cell vehicle 2 in Figure 6(a) described above. However, the number of hydrogen storage containers 100 loaded on the hydrogen trailer 3 is greater than that of the fuel cell vehicle 2, and the capacity of each hydrogen storage container 100 is also greater than that of the fuel cell vehicle 2. For example, the hydrogen trailer 3 may carry 24 hydrogen storage containers 100. Each hydrogen storage container 100 has a capacity of 300 L and an internal pressure of 45 MPa.

[0084] 1 is connected to a hydrogen supply port (not shown) of the hydrogen trailer 3 via a hydrogen supply pipe 101a. Hydrogen 100a is supplied from the hydrogen trailer 3 to a hydrogen storage tank at the hydrogen station via this hydrogen supply port. The operation of the disaster prevention equipment 1 shown in FIG. 6(b) in the event of a fire is the same as that of the fuel cell vehicle 2 in FIG. 6(a).

[0085] 5-3. Stationary equipment The disaster prevention equipment 1 of this embodiment is not limited to being installed in mobile vehicles such as the fuel cell vehicle 2 and hydrogen trailer 3 described above, but can also be installed in a stationary facility 4 shown in FIG. 6(c). The configuration of the disaster prevention equipment 1 installed in the stationary facility 4 is the same as in the case of the fuel cell vehicle 2 described above in FIG. 6(a). Furthermore, the operation of the disaster prevention equipment 1 shown in FIG. 6(c) in the event of a fire is also the same as in the case of the fuel cell vehicle 2 in FIG. 6(a).

[0086] 6. Action and Effects The disaster prevention equipment 1 of this embodiment, and the fuel cell vehicle 2, hydrogen trailer 3, and stationary equipment 4 equipped with this disaster prevention equipment 1 described above, can prevent the fusible plug type safety valve 102 from closing again, and also make it possible to visualize the jet flame of the hydrogen 100a released into the atmosphere. This makes it possible to avoid the rupture of the hydrogen storage container 100 in the event of a fire, and also makes it possible to prevent the spread of the fire by visually monitoring the jet flame of the hydrogen 100a.

[0087] 7.Other The disaster prevention equipment of the present invention, and the fuel cell vehicle, hydrogen trailer, and stationary equipment equipped with this disaster prevention equipment are not limited to the above-described embodiments. For example, the hydrogen storage container that is the object of protection of the disaster prevention equipment of the present invention is not limited to the form of a tank or cylinder such as a composite container. Furthermore, the hydrogen stored in the hydrogen storage container is not limited to the form of compressed hydrogen. The disaster prevention equipment of the present invention can be applied to containers that store various forms of hydrogen, such as liquefied hydrogen, organic hydrides (e.g., MCH), ammonia (NH), and hydrogen storage alloys.

[0088] 1 to 3, a hydrogen detector for detecting hydrogen leakage may be installed instead of the fire detector 30. Also, multiple first nozzles 14 may be installed for one hydrogen storage container 100. The multiple first nozzles 14 are, for example, lined up in the longitudinal direction of one hydrogen storage container 100, and installed at positions and oriented so that the fusible plug type safety valve 102 is not exposed to water.

[0089] A manual activation switch for activating the disaster prevention equipment 1 shown in Fig. 1 may be provided. By turning on this manual activation switch, a signal is sent to the control unit 40. This activates the pump 12 and opens the first electric valve 13. Furthermore, by turning on the manual activation switch, the control unit 40 ignites the initiator 22a and then opens the second electric valve 23.

[0090] The pump 12 may be omitted from the disaster prevention equipment 1 shown in FIG. 1. In this case, the cooling water tank 11 is installed at a higher position than the first nozzle 14, and the outlet of the cooling water tank 11 is connected to the inlet of the first motor-operated valve 13 via the first pipe 15. With this configuration, the cooling water 11a in the cooling water tank 11 can be supplied to the first nozzle 14 by the pressure caused by the difference in elevation between the cooling water tank 11 and the first nozzle 14. Furthermore, by applying a configuration similar to the pressurized container 22 and initiator 22a shown in FIG. 1 to the cooling water tank 11, the cooling water 11a in the cooling water tank 11 can also be supplied to the first nozzle 14.

[0091] The mixer 18 may be omitted from the disaster prevention equipment 1 shown in Fig. 3. In this case, the extinguishing agent 19a, which is a mixture of water and the extinguishing agent concentrate 17, is stored in the extinguishing agent tank 19. [Explanation of symbols]

[0092] 1 Disaster prevention equipment 11 Cooling water tank 11a Cooling water 12 Pump 13 First electric valve 14 No. 1 nozzle 14a Chip 14b Retainer 15 First Pipe 16 Orifice pipe 17 Fire extinguishing agent concentrate 18 Mixer 19 Fire extinguishing agent tank 19a Fire extinguishing agent 21 Aqueous solution tank 21a Sodium chloride solution 22 Pressurized vessels 22a Initiator 23 Second electric valve 24 Second nozzle 24a Chip 24b Retainer 25 Second piping 26 Venturi tube 26a Main pipe 26b Constriction section 26c Sub-pipeline 30 Fire detector 40 Control Unit 51, 52, 53 Shielding plate 100 Hydrogen storage container 100a Hydrogen 101 Former Barrister 101a Hydrogen supply piping 102 Fusible plug safety valve 102a Hydrogen release piping 2. Fuel cell vehicles 3 Hydrogen trailer 4 Stationary equipment

Claims

1. A disaster prevention system for cooling a hydrogen storage container equipped with a fusible plug type safety valve in the event of a fire, cooling water for cooling the hydrogen storage container; a first pipe for supplying the cooling water; a nozzle connected to the first pipe and capable of injecting the cooling water toward the hydrogen storage container; Equipped with A disaster prevention system characterized in that the fusible plug type safety valve is not exposed to water by the cooling water sprayed from the nozzle into the hydrogen storage container.

2. 2. The disaster prevention system according to claim 1, wherein the nozzle is disposed at a position where the fusible plug type safety valve is not wetted by the cooling water sprayed from the nozzle into the hydrogen storage container.

3. 3. The disaster prevention system according to claim 1, wherein the nozzle is installed in a direction such that the fusible plug type safety valve is not wetted by the cooling water sprayed from the nozzle into the hydrogen storage container.

4. 4. A disaster prevention system according to claim 1, wherein the cooling water is sprayed from the nozzle into the hydrogen storage container in a spray pattern that prevents the fusible plug type safety valve from becoming wet.

5. A disaster prevention system according to any one of claims 1 to 4, wherein the fusible plug type safety valve is prevented from being submerged in water by providing a shielding plate to block the cooling water from scattering and / or flowing in the direction of the fusible plug type safety valve.

6. 6. A disaster prevention system according to any one of claims 1 to 5, wherein the viscosity of the cooling water attached to the surface of the hydrogen storage container is increased by adding a substance that gives the cooling water thickening or gelling properties, thereby preventing the fusible plug type safety valve from becoming wet.

7. 7. The disaster prevention equipment according to claim 6, wherein the substance that gives the cooling water thickening or gelling properties is a substance having thixotropy.

8. 6. A disaster prevention system according to claim 1, wherein the surface tension of the cooling water relative to the surface of the hydrogen storage container is reduced by adding a substance that gives the cooling water wettability, thereby preventing the fusible plug type safety valve from becoming wet.

9. 9. The disaster prevention equipment according to claim 8, wherein the substance that imparts wettability to the cooling water is a surfactant.

10. A disaster prevention system according to any one of claims 1 to 9, wherein the hydrogen released from the hydrogen storage container through the fusible plug type safety valve is mixed with a substance that causes a flame color reaction.

11. 11. The disaster prevention equipment according to claim 10, further comprising a second pipe connected to the outlet of the fusible plug type safety valve, and wherein the substance that causes the flame color reaction is injected near the outlet of the second pipe, thereby mixing the substance that causes the flame color reaction with the hydrogen released from the hydrogen storage container.

12. 12. The disaster prevention equipment according to claim 10 or 11, wherein the substance that causes the flame color reaction is an aqueous sodium chloride solution.

13. a fire detector installed in the same location as the hydrogen storage container; a control unit that starts the supply of the cooling water based on a signal from the fire detector; The disaster prevention equipment according to any one of claims 1 to 12, comprising:

14. A fuel cell vehicle equipped with at least one hydrogen storage container fitted with a fusible plug type safety valve, the fuel cell vehicle comprising the disaster prevention equipment according to any one of claims 1 to 13.

15. A hydrogen trailer having a plurality of hydrogen storage containers fitted with fusible plug type safety valves loaded on a loading platform, the hydrogen trailer being equipped with the disaster prevention equipment according to any one of claims 1 to 13.

16. A stationary facility in which at least one hydrogen storage container equipped with a fusible plug type safety valve is installed, the stationary facility comprising the disaster prevention equipment according to any one of claims 1 to 13.

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