A fire-resistant high-pressure hydrogen storage cylinder and its preparation method

Abstract

The present invention provides a fire-resistant, high-pressure hydrogen storage cylinder and a method for preparing the same, relating to the technical field of hydrogen storage cylinders. The hydrogen storage cylinder of the present invention comprises a plastic liner, and a carbon fiber wrapping layer, a resin insulation layer, and a fire-resistant fiber wrapping layer sequentially disposed on the exterior of the plastic liner. By rationally disposing the carbon fiber wrapping layer, the resin insulation layer, and the fire-resistant fiber wrapping layer on the exterior of the plastic liner, the hydrogen storage cylinder overcomes the poor safety issues of existing fully wrapped composite material cylinders with plastic liner. The resulting hydrogen storage cylinder exhibits excellent fire resistance and thermal insulation properties, airtightness, and excellent weather resistance and fatigue resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen storage cylinders, and in particular relates to a fire-resistant high-pressure hydrogen storage cylinder and a preparation method thereof. Background Art

[0002] High-pressure hydrogen storage cylinders are important energy storage components for hydrogen fuel cell vehicles. Their storage medium, high-pressure hydrogen (35-70MPa), has a wide ignition range, low ignition energy, is prone to leakage and explosion, and has a fast flame propagation speed. As a result, they face high risks of leakage, combustion and explosion during actual use. In addition, the winding layer is generally made of carbon fiber, glass fiber, etc. The heat resistance temperature of carbon fiber generally does not exceed 300°C, and the heat resistance temperature of glass fiber is generally around 350°C. In the event of a fire, the temperature will quickly reach 800°C. The winding layer often cannot withstand high temperatures, resulting in reduced performance and an increased risk of cylinder explosion.

[0003] Furthermore, high-pressure hydrogen storage cylinders face safety issues during long-term use. For example, the interfacial bonding strength associated with fatigue resistance and weather resistance decreases. Long-term use or exposure to high and low temperatures can weaken the interfacial bonding strength between the wrapping layer and the liner, leading to delamination and reduced airtightness.

[0004] Therefore, the current composite material gas cylinders have great safety hazards during use, and it is necessary to design them reasonably to meet the needs. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and provide a fire-resistant high-pressure hydrogen storage cylinder and a preparation method thereof, thereby overcoming the problem of poor safety in the use of existing plastic liner fully wrapped composite material cylinders. The obtained hydrogen storage cylinder has good fire resistance and heat insulation properties, and excellent weather resistance and fatigue resistance.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] In one aspect, a fire-resistant high-pressure hydrogen storage cylinder comprises a plastic liner, and a carbon fiber winding layer, a resin isolation layer, and a fire-resistant fiber winding layer sequentially disposed on the outside of the plastic liner;

[0008] The resin isolation layer comprises the following raw materials in parts by weight: 80 to 100 parts of polyimide resin, 7 to 10 parts of modified SiO2 gel, 2 to 5 parts of flame retardant, and 3 to 5 parts of curing agent.

[0009] Furthermore, the modified SiO2 gel is prepared by a sol-gel method using tetraethyl orthosilicate and chlorosilane containing carbon-carbon unsaturated double bonds as silicon sources to prepare SiO2 wet gel, which is then immersed in a modification solution containing cinnamoyl chloride for surface modification.

[0010] The mechanical properties of traditional SiO2 gel are poor, which limits its application. The present invention first selects tetraethyl orthosilicate and chlorosilane containing carbon-carbon unsaturated double bonds as silicon sources to prepare a wet gel, which is then modified using cinnamoyl chloride. Cinnamoyl chloride undergoes a polymerization reaction with the carbon-carbon unsaturated double bonds on the surface of the SiO2 wet gel, so that the cinnamoyl chloride is coated on the surface of the gel skeleton in the form of a thin film, which has a good reinforcement and strengthening effect on the gel skeleton, and its mechanical strength and toughness are greatly improved, thereby increasing the strength of the resin isolation layer; after the SiO2 gel is modified, the interface compatibility and adhesion ability of the SiO2 gel and the polyimide resin are improved, the bonding strength of the entire resin isolation layer is increased, the SiO2 gel is dispersed more evenly in the coating, the specific surface area is increased, thereby reducing the heat transfer efficiency and improving the heat resistance; the introduction of cinnamoyl chloride into the surface of the modified SiO2 gel also helps to increase the bonding strength of the entire resin isolation layer, improve the flame retardant and heat insulating properties of the isolation layer, and improve the mechanical properties, fatigue aging resistance and weather resistance.

[0011] Preferably, the chlorosilane containing carbon-carbon unsaturated double bonds is selected from any one of dimethylvinylchlorosilane and 3-(methacryloyloxy)propyldimethylchlorosilane, or a combination of the two.

[0012] Preferably, the mass ratio of the tetraethyl orthosilicate to the chlorosilane containing carbon-carbon unsaturated double bonds is 1:(0.8-1).

[0013] Preferably, the mass ratio of cinnamoyl chloride to solvent in the modified liquid containing cinnamoyl chloride is (15-20):100.

[0014] Preferably, the solvent in the modified liquid containing cinnamoyl chloride is carbon tetrachloride.

[0015] Preferably, the loading amount of cinnamoyl chloride in the modified SiO2 gel is 7.2-10%.

[0016] The present invention provides a resin isolation layer between the carbon fiber winding layer and the fire-resistant fiber winding layer, which can enhance the flame retardant and heat-insulating effect of the high-pressure hydrogen storage cylinder, improve the mechanical properties, fatigue aging resistance and weather resistance, and avoid corrosion, deformation and the like in the gas storage cylinder during long-term use.

[0017] In a specific embodiment of the present invention, the modified SiO2 gel is prepared by the following method:

[0018] (1) adding a silicon source to ethanol and water, adding a surfactant and an acidic catalyst, and stirring the mixture to react to obtain a SiO2 wet gel;

[0019] (2) The SiO2 wet gel obtained in step (1) is aged and replaced with anhydrous ethanol 2 to 3 times, then immersed in a modification solution containing cinnamoyl chloride, an initiator is added and reacted for 16 to 20 hours, taken out, washed, and dried to obtain the modified SiO2 gel.

[0020] Preferably, in step (1), the mass ratio of the silicon source, surfactant, acidic catalyst, ethanol and water is 10:(15-30):(0.05-0.5):(0.2-0.5):(2-3).

[0021] Preferably, in step (1), the acidic catalyst is selected from any one or a combination of hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, oxalic acid, acetic acid, ammonium chloride, sodium bisulfate, and ammonium sulfate.

[0022] Preferably, in step (1), the surfactant is selected from any one or a combination of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, and tetradecylbetaine.

[0023] Preferably, in step (2), the initiator is selected from any one of azo initiators and peroxide initiators, or a combination of several of them.

[0024] Furthermore, the flame retardant in the resin isolation layer is selected from any one of melamine, isopropanolamine, and pentaerythritol, or a combination of several of them.

[0025] Preferably, the flame retardant in the resin isolation layer is melamine, isopropanolamine and pentaerythritol in a mass ratio of 1:(0.7-1):(0.2-0.4).

[0026] The present invention uses melamine, isopropanolamine and pentaerythritol as flame retardants, and has a better flame retardant effect than a single flame retardant. In addition, there is a certain synergistic effect between the flame retardant and the modified SiO2 gel, which helps to improve the air tightness of the gas cylinder, increase the flame retardant and heat insulation properties, and improve the fatigue aging resistance and weather resistance.

[0027] Furthermore, the curing agent in the resin isolation layer I is selected from any one or a combination of organic diamines, organic polyamines, organic diacids or organic polyacids.

[0028] Furthermore, the carbon fiber winding layer is formed by winding carbon fibers impregnated with an impregnation slurry, and the impregnation amount is 20-30%; wherein,

[0029] The impregnation slurry comprises the following raw materials in parts by weight: 100 parts of polyimide resin, 14-20 parts of polyurethane modified calcium carbonate microspheres, and 2-6 parts of curing agent.

[0030] In a specific embodiment of the present invention, the polyurethane-modified calcium carbonate microspheres are prepared by the following method:

[0031] (1) Dissolve calcium chloride, sodium carbonate and surfactant in water to prepare corresponding aqueous solutions; then dissolve the calcium chloride aqueous solution in water. 、 The surfactant aqueous solution is mixed and ultrasonically reacted at room temperature for 30 to 40 minutes, and then a sodium carbonate aqueous solution is added, and the temperature is lowered to 15 to 20°C and reacted for 2 to 3 hours. After the reaction, the mixture is centrifuged, washed with water, and dried to obtain calcium carbonate microspheres.

[0032] (2) dissolving the coupling agent in acetone, adding calcium carbonate microspheres, ultrasonically treating for 30 to 60 minutes, washing with water, and drying to obtain coupling agent-modified calcium carbonate microspheres;

[0033] (3) The dehydrated polyether diol is mixed with aromatic diisocyanate, and the mixture is reacted at 70-80°C for 1-2 hours. Ethylene bisoleamide, hydroxyethylidene diphosphonic acid, and coupling agent-modified calcium carbonate microspheres are added, and the reaction is continued for 2-3 hours. After the reaction is completed, the mixture is washed with water and dried to obtain polyurethane-modified calcium carbonate microspheres.

[0034] The present invention adds polyurethane-modified calcium carbonate microspheres to the impregnation slurry, so that the mutual attraction between the modified calcium carbonate microspheres is weakened and the dispersibility is enhanced, which helps to further increase the thermal insulation performance and improve the mechanical properties, and helps to further improve the mechanical properties of the gas cylinder. In addition, the introduction of ethylene bisoleamide and hydroxyethylidene diphosphonic acid into the modified calcium carbonate microspheres helps to increase flame retardancy and can increase the bonding of polyimide resin, thereby forming a dense cross-linked network structure and improving the airtightness of the gas cylinder.

[0035] Preferably, in step (1), the molar ratio of calcium chloride, sodium carbonate and surfactant is 1:(1-1.1):(0.02-0.04).

[0036] Preferably, in step (1), the surfactant is selected from any one of stearic acid and sodium lauryl sulfate, or a combination of the two.

[0037] Preferably, in step (2), the coupling agent is selected from any one of a titanate coupling agent and a silane coupling agent. The mass ratio of the coupling agent to the calcium carbonate microspheres is (0.1-0.2):1.

[0038] Preferably, in step (3), the aromatic diisocyanate is selected from any one of diphenylmethane diisocyanate (MDI) and toluene diisocyanate (TDI), or a combination of the two.

[0039] Preferably, in step (3), the mass ratio of the coupling agent-modified calcium carbonate microspheres, polyether diol, aromatic diisocyanate, ethylene bisoleamide, and hydroxyethylidene diphosphonic acid is 100:(8-10):(2-4):(1-1.5):(0.5-0.8).

[0040] Preferably, a catalyst is further added in step (3), and the amount of the catalyst added is 0.05-0.5% of the mass of the reaction raw materials; the catalyst is selected from any one or a combination of tin compounds, amines, and bismuth compounds.

[0041] Furthermore, the fire-resistant fiber winding layer is formed by winding fire-resistant fibers impregnated with the above-mentioned impregnation slurry; wherein, the fire-resistant fibers are selected from any one or a combination of basalt fibers, aluminum silicate fibers, alumina fibers, carbon fibers, mullite fibers, and quartz fibers.

[0042] In another aspect, a method for preparing a fire-resistant high-pressure hydrogen storage cylinder comprises the following steps:

[0043] S1. Liner manufacturing: high-density polyethylene (HDPE) or modified nylon 6 (modified PA6) injection molding;

[0044] S2, carbon fiber prepreg winding: the carbon fiber is impregnated with slurry and then wound on the surface of the plastic liner to form a carbon fiber winding layer;

[0045] S3. Spraying the resin isolation layer: spraying the slurry of the resin isolation layer evenly on the outside of the carbon fiber winding layer, and curing to form the resin isolation layer;

[0046] S4. Winding fire-resistant fibers: After being impregnated with slurry, the fire-resistant fibers are wound on the surface of the resin isolation layer and solidified to form a fire-resistant fiber winding layer.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The present invention provides a fire-resistant high-pressure hydrogen storage cylinder. By rationally arranging a carbon fiber winding layer, a resin isolation layer, and a fire-resistant fiber winding layer on the outside of a plastic liner, the hydrogen storage cylinder makes up for the poor safety problem of existing fully wound composite material cylinders with plastic liner. The obtained hydrogen storage cylinder has good fire resistance and heat insulation performance, and excellent weather resistance and fatigue resistance.

[0049] 2. The fire-resistant high-pressure hydrogen storage cylinder of the present invention effectively enhances the fire-resistant combustion performance of the cylinder and improves the safety of the composite material cylinder by providing a fire-resistant fiber winding layer and selecting fire-resistant fibers such as basalt.

[0050] 3. The fire-resistant high-pressure hydrogen storage cylinder of the present invention has a good flame retardant and heat-insulating effect by arranging a resin isolation layer outside the carbon fiber winding layer; the modified SiO2 gel is added to the resin isolation layer to improve the interface compatibility and adhesion ability of the SiO2 gel and the polyimide resin, increase the bonding strength of the entire resin isolation layer, and help improve the flame retardant and heat-insulating properties of the isolation layer, and improve the mechanical properties, fatigue aging resistance and weather resistance.

[0051] 4. The fire-resistant high-pressure hydrogen storage cylinder of the present invention uses melamine, isopropanolamine and pentaerythritol as flame retardants in the resin isolation layer, which has better flame retardant effect than a single flame retardant; in addition, there is a certain synergistic effect between the flame retardant and the modified SiO2 gel, which helps to improve the airtightness of the cylinder, increase the flame retardant and heat insulation properties, and improve the fatigue aging resistance and weather resistance.

[0052] 5. The fire-resistant high-pressure hydrogen storage cylinder of the present invention adds polyurethane-modified calcium carbonate microspheres to the impregnation slurry. After modification, the mutual attraction between the calcium carbonate microspheres is weakened and the dispersibility is enhanced, which helps to increase the thermal insulation performance to a certain extent. It can increase the bonding between the calcium carbonate microspheres and the polyimide resin, thereby forming a dense cross-linked network structure, improving the airtightness of the cylinder, and significantly improving the fatigue aging resistance and weather resistance of the cylinder. DETAILED DESCRIPTION

[0053] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following are merely illustrative of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0054] In a specific embodiment of the present invention, the curing agent can be selected from any one or more of organic diamines, organic polyamines, organic diacids or organic polyacids, for example, ethylenediamine, 1,3-propylenediamine, hexamethylenediamine, hydroxyethylethylenediamine, N,N'-diethyl-1,3-propylenediamine, 2-methylpentanediamine, 2-methyl-1,5-diaminopentane, isophoronediamine, methylcyclopentanediamine, 1,3-cyclopentanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, 2-methyl-1, 3-cyclohexanediamine, 1-methyl-2,4-cyclohexanediamine, 1-(aminomethyl)cyclopentylamine, 1-(aminomethyl)-N-methylcyclopentylamine, 4,4′-diaminodicyclohexylmethane, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, N,N′-dimethyl-1,2-cyclopentanediamine, N,N′-dimethyl-1,2-cyclohexanediamine, 2-aminocyclopentylmethylamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine are not particularly limited.

[0055] The present invention is further described below by way of specific examples. Unless otherwise specified, the various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels.

[0056] Example 1

[0057] This embodiment provides a fire-resistant high-pressure hydrogen storage cylinder, comprising a plastic liner, and a carbon fiber winding layer, a resin isolation layer, and a fire-resistant fiber winding layer sequentially arranged on the outside of the plastic liner; wherein,

[0058] The resin isolation layer slurry is prepared by uniformly mixing 80 parts of polyimide resin, 7 parts of modified SiO2 gel, 2 parts of flame retardant (melamine, isopropanolamine and pentaerythritol in a mass ratio of 1:0.7:0.2), and 3 parts of hexamethylenediamine;

[0059] The modified SiO2 gel was prepared by the following method:

[0060] (1) Add 10 parts of silicon source (ethyl orthosilicate and dimethylvinylchlorosilane in a mass ratio of 1:0.8) to 0.2 parts of ethanol and 3 parts of water, add 15 parts of sodium dodecylbenzenesulfonate and 0.1 parts of hydrofluoric acid, and stir to react to obtain SiO2 wet gel;

[0061] (2) The SiO2 wet gel obtained in step (1) was aged and replaced twice with anhydrous ethanol, and then immersed in carbon tetrachloride containing 15% by mass of cinnamoyl chloride, 0.1 parts of azobisisobutyronitrile was added and reacted for 16 hours, taken out, washed, and dried to obtain the modified SiO2 gel with a cinnamoyl chloride loading of 7.6%.

[0062] This embodiment also provides a method for preparing a fire-resistant high-pressure hydrogen storage cylinder, comprising the following steps:

[0063] S1. Liner manufacturing: HDPE is used to produce a plastic liner with a thickness of 5mm by blow molding;

[0064] S2, carbon fiber prepreg winding: the carbon fiber is treated with slurry (impregnation amount 20%), and then wound on the surface of the plastic liner, and cured to form a carbon fiber winding layer with a thickness of 28mm;

[0065] S3. Spraying resin isolation layer: spray the resin isolation layer slurry evenly on the outside of the carbon fiber winding layer by spraying, and solidify to form a resin isolation layer with a thickness of 0.6mm;

[0066] S4. Winding fire-resistant fiber: After the fire-resistant fiber is treated with an impregnating liquid, it is wound on the surface of the resin isolation layer and solidified to form a 0.8 mm fire-resistant fiber winding layer.

[0067] In this embodiment, the impregnation slurry in steps S2 and S3 is prepared by uniformly mixing 100 parts of polyimide resin, 14 parts of polyurethane-modified calcium carbonate microspheres, and 2 parts of hexamethylenediamine; wherein,

[0068] Polyurethane modified calcium carbonate microspheres were prepared by the following method:

[0069] (1) Calcium carbonate and sodium carbonate are dissolved in water to prepare a 0.1 mol / L aqueous solution, and sodium dodecyl sulfate is dissolved in water to prepare a 0.01 mol / L aqueous solution; then the calcium carbonate aqueous solution and the sodium dodecyl sulfate aqueous solution are mixed in a volume ratio of 5:1, ultrasonically reacted at room temperature for 30 minutes, and then an equal volume of sodium carbonate aqueous solution is added, and the temperature is lowered to 20°C for 2 hours; after the reaction is completed, the mixture is centrifuged, washed with water, and dried to obtain calcium carbonate microspheres;

[0070] (2) Dissolve 1 part of titanate coupling agent KR-38S in 50 g of acetone, add 10 parts of calcium carbonate microspheres, ultrasonically treat for 30 min, wash with water, and dry to obtain coupling agent-modified calcium carbonate microspheres;

[0071] (3) 0.8 parts of dehydrated polytetramethylene ether glycol and 0.2 parts of toluene diisocyanate were mixed and reacted at 70°C for 2 hours. 0.1 parts of ethylene bisoleamide, 0.05 parts of hydroxyethylidene diphosphonic acid, and 10 parts of coupling agent-modified calcium carbonate microspheres were added and the reaction was continued for 3 hours. The polyurethane-modified calcium carbonate microspheres were washed with water and dried to obtain the polyurethane-modified calcium carbonate microspheres.

[0072] Example 2

[0073] This embodiment provides another fire-resistant high-pressure hydrogen storage cylinder, comprising a plastic liner, and a carbon fiber winding layer, a resin isolation layer, and a fire-resistant fiber winding layer sequentially arranged on the outside of the plastic liner; wherein,

[0074] The resin isolation layer slurry is prepared by uniformly mixing 100 parts of polyimide resin, 10 parts of modified SiO2 gel, 5 parts of flame retardant (melamine, isopropanolamine and pentaerythritol in a mass ratio of 1:1:0.4), and 5 parts of hexamethylenediamine;

[0075] The modified SiO2 gel was prepared by the following method:

[0076] (1) Add 10 parts of silicon source (ethyl orthosilicate and 3-(methacryloyloxy)propyldimethylchlorosilane in a mass ratio of 1:1) to 0.3 parts of ethanol and 2 parts of water, add 30 parts of sodium dodecylbenzenesulfonate and 0.1 parts of hydrofluoric acid, and stir to react to obtain SiO2 wet gel;

[0077] (2) The SiO2 wet gel obtained in step (1) was aged and replaced twice with anhydrous ethanol, then immersed in carbon tetrachloride containing 15% by mass of cinnamoyl chloride, 0.2 parts of azobisisobutyronitrile was added and reacted for 20 hours, taken out, washed, and dried to obtain the modified SiO2 gel with a cinnamoyl chloride loading of 9.1%.

[0078] This embodiment also provides another method for preparing a fire-resistant high-pressure hydrogen storage cylinder, comprising the following steps:

[0079] S1. Liner manufacturing: HDPE is used to produce a plastic liner with a thickness of 5mm by blow molding;

[0080] S2. Carbon fiber prepreg winding: After the carbon fiber is impregnated with slurry (30% impregnation), it is wound on the surface of the plastic liner and cured to form a carbon fiber winding layer with a thickness of 28 mm;

[0081] S3. Spraying resin isolation layer: spray the resin isolation layer slurry evenly on the outside of the carbon fiber winding layer by spraying, and solidify to form a resin isolation layer with a thickness of 0.6mm;

[0082] S4. Winding fire-resistant fiber: After the fire-resistant fiber is treated with an impregnating liquid, it is wound on the surface of the resin isolation layer and solidified to form a 0.8 mm fire-resistant fiber winding layer.

[0083] In this embodiment, the impregnation slurry in steps S2 and S3 is prepared by uniformly mixing 100 parts of polyimide resin, 20 parts of polyurethane-modified calcium carbonate microspheres, and 6 parts of hexamethylenediamine; wherein,

[0084] Polyurethane modified calcium carbonate microspheres were prepared by the following method:

[0085] (1) Calcium carbonate and sodium carbonate are dissolved in water to prepare a 0.1 mol / L aqueous solution, and sodium dodecyl sulfate is dissolved in water to prepare a 0.01 mol / L aqueous solution; then the calcium carbonate aqueous solution and the sodium dodecyl sulfate aqueous solution are mixed in a volume ratio of 5:1, ultrasonically reacted at room temperature for 40 minutes, and then an equal volume of sodium carbonate aqueous solution is added, and the temperature is lowered to 15°C for 3 hours; after the reaction, the mixture is centrifuged, washed with water, and dried to obtain calcium carbonate microspheres;

[0086] (2) Dissolve 2 parts of titanate coupling agent KR-38S in 50 g of acetone, add 10 parts of calcium carbonate microspheres, ultrasonically treat for 50 min, wash with water, and dry to obtain coupling agent-modified calcium carbonate microspheres;

[0087] (3) 1 part of dehydrated polytetramethylene ether glycol was mixed with 0.4 parts of toluene diisocyanate, and the mixture was reacted at 80°C for 1 hour. 0.15 parts of ethylene bisoleamide, 0.08 parts of hydroxyethylidene diphosphonic acid, and 10 parts of coupling agent-modified calcium carbonate microspheres were added, and the reaction was continued for 3 hours. The polyurethane-modified calcium carbonate microspheres were washed with water and dried.

[0088] Example 3

[0089] The difference from Example 1 is that in the preparation process of the modified SiO2 gel in this example, dimethylvinylchlorosilane is replaced by an equal amount of vinyltriethoxysilane.

[0090] Example 4

[0091] The difference from Example 1 is that the flame retardant of the resin isolation layer slurry of this embodiment is only melamine and isopropanolamine in a mass ratio of 1:0.7.

[0092] Example 5

[0093] The difference from Example 1 is that the flame retardant of the resin isolation layer slurry of this embodiment is melamine and pentaerythritol in a mass ratio of 1:0.2.

[0094] Example 6

[0095] The difference from Example 1 is that the flame retardant of the resin isolation layer slurry of this embodiment is isopropanolamine and pentaerythritol in a mass ratio of 0.7:0.2.

[0096] Comparative Example 1

[0097] The difference from Example 1 is that in the preparation process of the modified SiO2 gel in this comparative example, the silicon source is only ethyl orthosilicate.

[0098] Comparative Example 2

[0099] The difference from Example 1 is that the modified SiO2 gel in this comparative example is replaced by an equal amount of unmodified SiO2 gel; the SiO2 gel is prepared by the following method: 10 parts of silicon source (ethyl orthosilicate and 3-(methacryloyloxy)propyldimethylchlorosilane in a mass ratio of 1:1) are added to 0.3 parts of ethanol and 2 parts of water, 30 parts of sodium dodecylbenzenesulfonate and 0.1 parts of hydrofluoric acid are added, and the reaction is stirred to obtain SiO2 wet gel, which is then aged, replaced with anhydrous ethanol twice, and dried.

[0100] Comparative Example 3

[0101] The difference from Example 1 is that no modified SiO2 gel is added to the resin isolation layer slurry of this comparative example.

[0102] Comparative Example 4

[0103] The difference from Example 1 is that, in the preparation process of the polyurethane-modified calcium carbonate microspheres in this comparative example, ethylene bisoleamide was not added.

[0104] Comparative Example 5

[0105] The difference from Example 1 is that, in the preparation process of the polyurethane-modified calcium carbonate microspheres in this comparative example, no hydroxyethylidene diphosphonic acid was added.

[0106] Comparative Example 6

[0107] The difference from Example 1 is that the polyurethane-modified calcium carbonate microspheres in this comparative example are replaced by an equal amount of unmodified calcium carbonate microspheres.

[0108] Comparative Example 7

[0109] The difference from Example 1 is that polyurethane-modified calcium carbonate microspheres are not added to the impregnation slurry of this comparative example.

[0110] Test Example 1

[0111] The hydrogen storage cylinders prepared in the above examples and comparative examples were tested for hydrogen permeability in accordance with GB / T42610-2023. The hydrogen storage cylinders were also tested for minimum burst pressure, aging resistance, and weather resistance in accordance with GB / T42612-2023. Aging resistance was evaluated using the number of normal-temperature pressure cycle failures (cycles A); weather resistance was evaluated using the number of low-temperature pressure cycle failures at -40°C (cycles B) and high-temperature pressure cycle failures at 270°C (cycles C). The results are shown in Table 1 below.

[0112] Table 1

[0113]

[0114] As shown in the table, the hydrogen permeability coefficient of the hydrogen storage cylinder provided by the present invention can reach 2.0×10 -15 cm 3 cm / (cm 2 ·s·Pa), good airtightness, minimum bursting pressure of more than 200MPa, number of cycle failures under normal temperature pressure of more than 49,000 times, excellent anti-aging performance, number of cycle fatigue failures under -40℃ ambient temperature of more than 7,000 times, number of cycle fatigue failures under 270℃ ambient temperature of more than 7,000 times, and good weather resistance.

[0115] Test Example 2

[0116] The hydrogen storage cylinders prepared in the above examples and comparative examples were subjected to fire resistance tests and thermal insulation performance tests. During the fire resistance test, the hydrogen storage cylinders were cut into 10×10 cm specimens, exposed to flame for 60 seconds, and observed to see if the cylinders burned. The results are shown in Table 2.

[0117] Table 2

[0118] Group Thermal conductivity W / (m·K) Example 1 0.016 Example 2 0.019 Example 3 0.055 Example 4 0.086 Example 5 0.092 Example 6 0.095 Comparative Example 1 0.067 Comparative Example 2 0.104 Comparative Example 3 0.081 Comparative Example 4 0.048 Comparative Example 5 0.051 Comparative Example 6 0.048 Comparative Example 7 0.058

[0119] Testing revealed that the sample did not burn when exposed to a fire source. However, the hydrogen storage cylinder samples obtained in Comparative Examples 2 and 3 exhibited flames, but the flames extinguished automatically about one minute after removal from the fire source. Therefore, the high-pressure hydrogen storage cylinders provided by the present invention exhibit excellent fire resistance and flame retardancy, remedying the poor fire resistance and flame retardancy of existing hydrogen storage cylinders.

[0120] As shown in the table above, the thermal conductivity of the sample is no higher than 0.02W / (m·K). The low thermal conductivity can effectively prevent heat conduction and improve the safety of hydrogen storage cylinders in high temperature or fire environments.

[0121] In summary, the embodiments of the present invention provide a fire-resistant high-pressure hydrogen storage cylinder and a preparation method thereof, by arranging a carbon fiber winding layer, a resin isolation layer and a fire-resistant fiber winding layer on the outside of a plastic liner, introducing modified SiO2 gel into the resin isolation layer, and combining with compound flame retardants melamine, isopropanolamine and pentaerythritol, and introducing polyurethane-modified calcium carbonate microspheres into the carbon fiber winding layer and the fire-resistant fiber winding layer, so as to provide the high-pressure cylinder with good fire-retardant and heat-insulating properties, and improve the minimum bursting pressure, air tightness, fatigue resistance and weather resistance of the hydrogen storage cylinder, so that the cylinder can be used safely for a long time under higher pressure levels and complex environmental conditions.

[0122] The above description of the embodiments is intended to facilitate understanding and application of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A fire-resistant high-pressure hydrogen storage cylinder, characterized in that: It comprises a plastic liner, and a carbon fiber winding layer, a resin isolation layer and a fire-resistant fiber winding layer sequentially arranged on the outside of the plastic liner; The resin isolation layer comprises the following raw materials in parts by weight: 80-100 parts of polyimide resin, 7-10 parts of modified SiO2 gel, 2-5 parts of flame retardant, and 3-5 parts of curing agent; The modified SiO2 gel is prepared by a sol-gel method using ethyl orthosilicate and chlorosilane containing carbon-carbon unsaturated double bonds as silicon sources to prepare SiO2 wet gel, which is then immersed in a modification solution containing cinnamoyl chloride for surface modification.

2. The fire-resistant high-pressure hydrogen storage cylinder according to claim 1, characterized in that: The chlorosilane containing carbon-carbon unsaturated double bonds is selected from any one of dimethylvinylchlorosilane and 3-(methacryloyloxy)propyldimethylchlorosilane, or a combination of the two.

3. The fire-resistant high-pressure hydrogen storage cylinder according to claim 1, characterized in that: The mass ratio of the tetraethyl orthosilicate to the chlorosilane containing carbon-carbon unsaturated double bonds is 1:(0.8-1).

4. The fire-resistant high-pressure hydrogen storage cylinder according to claim 1, characterized in that: The flame retardant in the resin isolation layer is selected from any one of melamine, isopropanolamine and pentaerythritol or a combination of several of them.

5. The fire-resistant high-pressure hydrogen storage cylinder according to claim 4, characterized in that: The flame retardant in the resin isolation layer is melamine, isopropanolamine and pentaerythritol in a mass ratio of 1:(0.7-1):(0.2-0.4).

6. The fire-resistant high-pressure hydrogen storage cylinder according to claim 1, characterized in that: The carbon fiber winding layer is formed by winding carbon fibers impregnated with an impregnation slurry; wherein, The impregnation slurry comprises the following raw materials in parts by weight: 100 parts of polyimide resin, 14-20 parts of polyurethane modified calcium carbonate microspheres, and 2-6 parts of curing agent.

7. The fire-resistant high-pressure hydrogen storage cylinder according to claim 6, characterized in that: The polyurethane modified calcium carbonate microspheres are prepared by the following method: (1) Mixing a calcium carbonate aqueous solution and a surfactant aqueous solution, ultrasonically reacting at room temperature, and then adding a sodium carbonate aqueous solution for reaction; after the reaction, centrifuging, washing with water, and drying to obtain calcium carbonate microspheres; (2) dissolving the coupling agent in acetone, adding calcium carbonate microspheres, ultrasonically treating, washing with water, and drying to obtain coupling agent-modified calcium carbonate microspheres; (3) The dehydrated polyether diol is mixed with aromatic diisocyanate for reaction, and ethylene bisoleamide, hydroxyethylidene diphosphonic acid, and coupling agent-modified calcium carbonate microspheres are added and the reaction is continued; after the reaction is completed, the mixture is washed with water and dried to obtain polyurethane-modified calcium carbonate microspheres.

8. The fire-resistant high-pressure hydrogen storage cylinder according to claim 7, characterized in that: The mass ratio of the coupling agent modified calcium carbonate microspheres, polyether diol, aromatic diisocyanate, ethylene bisoleamide and hydroxyethylidene diphosphonic acid is 100:(8-10):(2-4):(1-1.5):(0.5-0.8).

9. The fire-resistant high-pressure hydrogen storage cylinder according to claim 7, characterized in that: The fire-resistant fiber winding layer is formed by winding fire-resistant fibers impregnated with the impregnation slurry.

10. The method for preparing the fire-resistant high-pressure hydrogen storage cylinder according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Liner manufacturing: HDPE or modified PA6 injection molding; S2, carbon fiber prepreg winding: the carbon fiber is impregnated with slurry and then wound on the surface of the plastic liner to form a carbon fiber winding layer; S3. Spraying the resin isolation layer: spraying the slurry of the resin isolation layer evenly on the outside of the carbon fiber winding layer, and curing to form the resin isolation layer; S4. Winding fire-resistant fibers: After being impregnated with slurry, the fire-resistant fibers are wound on the surface of the resin isolation layer and solidified to form a fire-resistant fiber winding layer.

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