Composite hydrogen conveying pipeline and preparation process thereof

Abstract

The composite hydrogen conveying pipeline is sequentially provided with a hydrogen blocking coating, a hydrogen storage composite layer, a metal pipe layer and an outer protection layer from inside to outside, the hydrogen blocking coating is formed by coating a coating prepared from a hydrogen blocking material, the hydrogen storage composite layer is a composite pipeline prepared from a hydrogen storage material, the metal pipe layer is a film-coated steel pipe, and the outer protection layer is a metal pipe. And the outer protection layer is a protection layer prepared from fluorinated plastics and is prepared step by step through material preparation, pretreatment, pipeline processing and compounding processes and a spraying process. The invention has the beneficial effects that the permeation of hydrogen to the inner wall of the pipeline is greatly reduced and slowed down through the hindering of the hydrogen-resistant coating layer and the absorption cooperation of the hydrogen storage composite layer, and then the hydrogen-resistant capability is improved layer by layer through the combination of the high hydrogen-resistant permeation capability of the metal coating of the metal pipe, so that the hydrogen-resistant performance is improved. And meanwhile, after hydrogen and the hydrogen storage composite layer are combined, the hydrogen permeability is further reduced, and the hydrogen resistance capacity of the pipeline is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field related to hydrogen transmission pipelines, and in particular to a composite hydrogen transmission pipeline and a preparation process thereof. Background Art

[0002] With the continuous growth of global energy demand and the increasing attention to environmental protection, the development of new energy has become increasingly important. In the field of new energy, hydrogen energy, as a clean and renewable energy, has received extensive attention and application as a clean and efficient energy form. It has broad application prospects in many fields such as industrial production, energy storage, fuel cell vehicles, aerospace, etc., and has gradually become an important part of the global energy transformation. With the global promotion of low-carbon economy and the increasing demand for renewable energy, the prospect of hydrogen energy utilization has become broader, especially in the production and transportation of green hydrogen energy. Hydrogen, as an efficient and environmentally friendly energy carrier, has been paid attention to by more and more countries and regions. However, the special properties of hydrogen make it face many technical challenges in the storage and transportation process.

[0003] The high energy density and clean properties of hydrogen give it great potential in many industries, but the storage and transportation of hydrogen remains a key bottleneck for its large-scale application. Compared with traditional fossil energy, the physical and chemical properties of hydrogen make it significantly challenging to apply on a large scale. Hydrogen has a large volume at room temperature and pressure, and the safety, economy, and efficiency of its storage and transportation directly affect the development of the hydrogen energy industry. Therefore, the production, storage, transportation, and distribution of hydrogen energy have become one of the important directions of current technological research. As one of the main ways to transport hydrogen, hydrogen pipelines have important technical significance and market value.

[0004] Hydrogen molecules are small, highly permeable, and easily cause hydrogen embrittlement under high pressure. Hydrogen embrittlement refers to the embrittlement of metal materials under the action of hydrogen. Hydrogen molecules penetrate metal structures in high pressure or low temperature environments, causing the strength and ductility of the metal to decrease, and in severe cases, rupture or damage may occur. The hydrogen embrittlement problem mainly occurs in high-strength steel, aluminum alloys and other commonly used pipeline materials. Therefore, the design of hydrogen pipelines needs to select materials that are resistant to hydrogen embrittlement, and optimize and improve the hydrogen embrittlement performance of existing materials. Prevent the mechanical properties of the material and the safety of the pipeline from being affected. In addition, the high-pressure transmission of hydrogen requires reliable sealing and structural strength, which puts higher requirements on the design and material selection of hydrogen pipelines. In order to meet these requirements, hydrogen pipelines must have multiple properties such as preventing hydrogen penetration, resisting hydrogen embrittlement, corrosion resistance, and high strength.

[0005] At present, some countries in the world have begun to explore the transformation of natural gas pipelines to adapt to the transportation of hydrogen. For example, in countries such as Germany and the Netherlands, some natural gas pipelines have been transformed into hydrogen pipelines. This type of transformation usually improves its hydrogen resistance by strengthening the pipeline material, optimizing the sealing design, and protecting the pipeline from corrosion. However, due to the permeability of hydrogen to pipeline materials and the existence of hydrogen embrittlement, the transformation of natural gas pipelines is not completely suitable for the long-term transportation of hydrogen. Summary of the invention

[0006] In view of the above shortcomings, the present invention aims to provide a composite hydrogen pipeline and its preparation process, and a composite pipeline with strong hydrogen resistance, hydrogen embrittlement resistance, corrosion resistance and high strength is prepared by compounding multiple materials to make up for the shortcomings of the current high-pressure hydrogen pipeline. The following technical solutions:

[0007] A composite hydrogen transmission pipeline and a preparation process thereof, wherein the pipeline is provided with a hydrogen barrier coating, a hydrogen storage composite layer, a metal tube layer and an outer protective layer in sequence from the inside to the outside;

[0008] The hydrogen barrier coating is a composite coating, and its components include 60-70 parts of polytetrafluoroethylene PTFE, 25-35 parts of epoxy resin, 0.8-1.2 parts of crosslinking agent, 5-10 parts of metal oxide filler, 5-10 parts of nitride boron nitride, 3-5 parts of dispersant, 1-2 parts of curing agent, 20-30 parts of cyclohexane, etc.

[0009] The hydrogen storage composite layer comprises 70-80 parts by weight of polyetheretherketone PEEK, 10-15 parts by weight of fluorinated ethylene propylene copolymer FEP, 2-3 parts by weight of polyethylene wax, 0.5-1 parts by weight of polyethyleneimine PEI, 0.2-0.5 parts by weight of polyacrylate, 2-3 parts by weight of graphene oxide, 5-10 parts by weight of MOFs material, and 4-5 parts by weight of talc powder;

[0010] The metal tube layer is plated with a metal coating, and the thickness of the coating is 0.3-0.5 mm;

[0011] The outer protective layer is a tubular structure made of fluorinated plastic.

[0012] Furthermore, the thickness of the hydrogen barrier coating is 200 μm to 500 μm.

[0013] Furthermore, the ratio of the inner diameter of the metal tube to the wall thickness in the metal tube layer is 20:1, and the metal coating is aluminum coating, nickel coating, titanium coating and molybdenum coating, preferably nickel coating.

[0014] Furthermore, the MOFs material used in the hydrogen storage composite layer is ZIF-8 or MOF-5.

[0015] Furthermore, in the hydrogen barrier coating, the crosslinking agent is tert-butyl peroxide (TBHP), the curing agent is diethylenetriamine, and the dispersant includes 2 to 3 parts of trioctyl phosphate (TPP) and 1 to 2 parts of sodium dodecylbenzene sulfonate.

[0016] Furthermore, the fluorinated plastic used in the outer protective layer is one of polytetrafluoroethylene, polyvinylidene fluoride (PVDF) and fluorinated ethylene-propylene copolymer (FEP), preferably polytetrafluoroethylene.

[0017] Furthermore, the thickness ratio of the hydrogen storage composite layer to the metal tube layer is 0.3-0.5:1.

[0018] Furthermore, the thickness ratio of the metal tube layer to the outer protective layer is 1:0.4-0.6.

[0019] Furthermore, the metal oxide used in the hydrogen barrier coating is a mixture of one or more of aluminum oxide, titanium oxide, molybdenum oxide and cobalt oxide, preferably titanium oxide and aluminum oxide.

[0020] A preparation process of a composite hydrogen transmission pipeline comprises the following steps:

[0021] S1. Material preparation

[0022] X80 seamless steel pipe; polytetrafluoroethylene PTFE, epoxy resin, crosslinking agent tert-butyl peroxide TBHP, metal oxide fillers aluminum oxide, titanium oxide, molybdenum oxide and cobalt oxide, nitride boron nitride, dispersant trioctyl phosphate, sodium dodecylbenzene sulfonate, curing agent diethylenetriamine, cyclohexane; polyetheretherketone PEEK, fluorinated ethylene propylene copolymer FEP, polyethylene wax, polyethyleneimine PEI, polyacrylate, graphene oxide, MOFs material, talc, melting reducer triphenylphosphine; fluorinated plastic polytetrafluoroethylene, polyvinylidene fluoride (PVDF) and fluorinated ethylene-propylene copolymer;

[0023] S2. Material Pretreatment

[0024] The hydrogen barrier coating is prepared according to the corresponding mass parts of raw materials used in the formula, mixed evenly, and placed in a container for standby use to obtain coating L1; the raw materials used in the formula are melt-extruded through an extruder to form a hydrogen storage composite layer material pipeline, cooled, polished, and cut into pipelines L2 corresponding to the length of the steel pipe;

[0025] S3. Pipeline Processing

[0026] X80 seamless steel pipe surface treatment, then electroplating 0.3 ~ 0.5mm metal coating;

[0027] S4. Pipeline Composite

[0028] The surface of the metal-plated X80 seamless steel pipe is sandblasted, a hydrogen storage composite layer is compounded on the inner wall of the steel pipe using the hydrogen storage material L2 through a hot pressing composite process, and then the outer protective layer formed by the fluorinated plastic is compounded on the outer wall of the obtained steel pipe through an extruder,

[0029] S5. Paint spraying

[0030] The hydrogen barrier coating L1 is sprayed onto the inner wall of the pipe obtained in the previous step by a spraying machine, and then dried and solidified with hot air at 40-60°C to obtain a finished pipe G;

[0031] S6. Pipeline inspection

[0032] Perform corresponding inspection on pipeline G through the inspection device;

[0033] S7. Packaging and storage

[0034] Qualified pipes that pass the inspection are packed with polyethylene film to avoid dust accumulation and prevent damage during transportation.

[0035] The beneficial effects of the present invention are as follows: 1. The present invention greatly reduces and slows down the penetration of hydrogen into the inner wall of the pipeline through the barrier of the hydrogen barrier coating layer and the absorption of the hydrogen storage composite layer, and then through the high hydrogen permeation resistance of the metal coating of the metal pipe, the hydrogen permeation capacity on both sides of the hydrogen storage composite layer is different, so that when the hydrogen in the hydrogen storage composite layer in the pipeline is separated, it penetrates into the pipeline and returns to the inside of the transmission pipeline, thereby avoiding hydrogen from penetrating the metal pipe coating to cause hydrogen embrittlement, and further increasing the hydrogen resistance of the pipeline; 2. The pipeline obtained by the present invention has high strength, strong pressure resistance, and good corrosion resistance, which can effectively increase the service life of the pipeline, which is conducive to reducing the number of maintenance and replacement, saving maintenance costs, and the high strength and high hydrogen resistance characteristics also greatly improve the safety of the transmission pipeline; 3. The hydrogen storage material of the present invention has strong hydrogen storage capacity and good hydrogen storage effect, and the permeability of the stored hydrogen is further reduced, so that the coating can easily prevent it from continuing to penetrate outward, and the hydrogen resistance is further improved. In addition, when the hydrogen pressure in the pipeline fluctuates, the hydrogen released by the hydrogen storage material can adjust the inside of the pipeline to a certain extent to control the balance in the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic cross-sectional view of the pipeline structure of the present invention.

[0037] In the figure: 1-hydrogen barrier coating, 2-hydrogen storage composite layer, 3-metal tube layer, 4-outer protective layer. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Combination Figure 1 Shown:

[0040] A composite hydrogen transmission pipeline, the pipeline structure is:

[0041] The pipeline is provided with a hydrogen barrier coating 1, a hydrogen storage composite layer 2, a metal tube layer 3 and an outer protective layer 4 in sequence from the inside to the outside; the hydrogen barrier coating 1 has a thickness of 200 μm to 500 μm; the metal tube layer 3 is plated with a metal coating (one of aluminum plating, nickel plating, titanium plating and molybdenum plating, with a thickness of 0.3 to 0.5 mm), and the ratio of the inner diameter of the metal tube in the metal tube layer to the wall thickness is 20:1; the outer protective layer 4 is a pipe made of a fluorinated plastic such as polytetrafluoroethylene, polyvinylidene fluoride (PVDF) and fluorinated ethylene-propylene copolymer (FEP). The thickness ratio of the hydrogen storage composite layer 2 to the metal tube layer is 0.3 to 0.5:1; the thickness ratio of the metal tube layer 3 to the outer protective layer 4 is 1:0.4 to 0.6.

[0042] The specific steps for pipeline preparation are as follows:

[0043] S1. Material preparation

[0044] X80 seamless steel pipe (nickel-plated, inner diameter φ300, wall thickness 15mm);

[0045] 1. Hydrogen barrier coating

[0046] Polytetrafluoroethylene PTFE (Sinopec PTFE2000), epoxy resin (E-44), cross-linking agent diphenylmethane diisocyanate MDI (standardized reagent), metal oxide filler (aluminum oxide, titanium oxide, molybdenum oxide and cobalt oxide, one or more mixtures, all standardized reagents, and the particle size is sieved to be 1-10μm powder), nitride boron nitride (standardized hexagonal boron nitride powder), dispersant (including trioctyl phosphate TPP and sodium dodecylbenzene sulfonate, standardized reagents), curing agent diethylenetriamine (standardized reagent), cyclohexane (analytical grade), etc.;

[0047] 2. Hydrogen storage composite layer

[0048] Polyetheretherketone PEEK (VICTREX450G), fluorinated ethylene propylene copolymer FEP (polyperfluoroethylene propylene FEP, F46), polyethylene wax (PODAX S-105 polyethylene micronized wax), polyethyleneimine PEI (Sigma-Aldrich PEI Mw 25000), polyacrylate (BASF Rheovis 1910), graphene oxide (Merck standardized reagent), MOFs material (ZIF-8 or MOF-5, commercially purchased standardized reagent), talc (standardized reagent), melting depressant triphenylphosphine (standardized reagent);

[0049] Hydrogen barrier coating Z-1

[0050] The components of the hydrogen barrier coating include 60 parts of polytetrafluoroethylene (PTFE), 25 parts of epoxy resin, 0.8 parts of diphenylmethane diisocyanate (MDI), 5 parts of titanium oxide (metal oxide filler), 5 parts of boron nitride (nitride), 3 parts of dispersant (including 2 parts of trioctyl phosphate (TPP) and 1 part of sodium dodecylbenzene sulfonate), 1 part of curing agent diethylenetriamine, 20 parts of cyclohexane, etc.

[0051] Hydrogen barrier coating Z-2

[0052] The components of the hydrogen barrier coating include 70 parts of polytetrafluoroethylene (PTFE), 35 parts of epoxy resin, 1.2 parts of crosslinking agent diphenylmethane diisocyanate (MDI), 10 parts of metal oxide filler titanium oxide, 10 parts of nitride boron nitride, 5 parts of dispersant (including 3 parts of trioctyl phosphate (TPP) and 2 parts of sodium dodecylbenzene sulfonate), 2 parts of curing agent diethylenetriamine, 30 parts of cyclohexane, etc.

[0053] Hydrogen barrier coating Z-3

[0054] The components of the hydrogen barrier coating include 60 parts of polytetrafluoroethylene (PTFE), 25 parts of epoxy resin, 0.8 parts of diphenylmethane diisocyanate (MDI), 5 parts of metal oxide filler (aluminum oxide), 5 parts of nitride (boron nitride), 3 parts of dispersant (including 2 parts of trioctyl phosphate (TPP) and 1 part of sodium dodecylbenzene sulfonate), 1 part of curing agent (diethylenetriamine), 20 parts of cyclohexane, etc.

[0055] Hydrogen storage composite layer C-1

[0056] The hydrogen storage composite layer includes 70 parts by weight of polyetheretherketone PEEK, 10 parts by weight of fluorinated ethylene propylene copolymer FEP, 2 parts by weight of polyethylene wax, 0.5 parts by weight of polyethyleneimine PEI, 0.2 parts by weight of polyacrylate, 2 parts by weight of graphene oxide, 5 parts by weight of MOFs material ZIF-8, 4 parts by weight of talc powder, and 5 parts by weight of triphenylphosphine, a flux reducing agent;

[0057] Hydrogen storage composite layer C-2

[0058] The hydrogen storage composite layer includes 80 parts of polyetheretherketone PEEK, 15 parts of fluorinated ethylene propylene copolymer FEP, 3 parts of polyethylene wax, 1 part of polyethyleneimine PEI, 0.5 parts of polyacrylate, 3 parts of graphene oxide, 10 parts of MOFs material ZIF-8, 5 parts of talc powder, and 10 parts of triphenylphosphine, a flux reducing agent;

[0059] Hydrogen storage composite layer C-3.

[0060] The hydrogen storage composite layer includes 70 parts by weight of polyetheretherketone PEEK, 10 parts by weight of fluorinated ethylene propylene copolymer FEP, 2 parts by weight of polyethylene wax, 0.5 parts by weight of polyethyleneimine PEI, 0.2 parts by weight of polyacrylate, 2 parts by weight of graphene oxide, 5 parts by weight of MOFs material MOF-5, 4 parts by weight of talc powder, and 5 parts by weight of triphenylphosphine, a flux reducer.

[0061] S2. Material Pretreatment

[0062] The hydrogen barrier coating is prepared according to the corresponding mass parts of raw materials used in the above hydrogen barrier coating formula, mixed evenly, and placed in a container for standby use to obtain the hydrogen barrier coating:

[0063] PTFE is mixed with 2 / 3 parts by mass of cyclohexane solvent and dispersed with a high-speed stirrer until a uniform suspension is obtained, and then epoxy resin is added to a stirring container, and the remaining parts by mass of cyclohexane are added, and stirred evenly, and then the PTFE suspension is gradually added to the obtained epoxy resin solution, and stirring is continued until the PTFE is completely dispersed and interacts with the epoxy resin to form a uniform base; during the stirring process, titanium oxide filler, boron nitride filler and dispersant mixture are gradually added, a crosslinking agent is added, a curing agent is added, stirred evenly, and ultrasonic mixing is performed to obtain a coating L1 corresponding to the hydrogen barrier coating;

[0064] The hydrogen storage composite layer material is prepared according to the mass parts of raw materials used in the formula, mixed evenly, and placed in a container for standby use to obtain the hydrogen storage material:

[0065] Polyetheretherketone PEEK is melted at 350°C, and fluorinated ethylene propylene copolymer FEP, polyethylene wax, and polyethyleneimine PEI are added, mixed and stirred, and triphenylphosphine phosphine and talcum powder, a melting depressant, are added, and the melting temperature is reduced to 280°C. At this time, polyacrylate, graphene oxide, and MOFs material MOF-5 are added, and the pipe L2 is extruded through an extruder.

[0066] S3. Pipeline Processing

[0067] Use appropriate cleaning agents to remove impurities such as oil, grease, and dust on the surface of the X80 pipe. Hydrochloric acid pickling is used to remove the oxide scale and rust on the surface of the pipe to ensure good adhesion of the nickel plating layer, and then electroplating nickel 0.3-0.5mm;

[0068] S4. Pipeline Composite

[0069] The surface of the X80 seamless steel pipe with the metal coating is sandblasted, and the pipe L2 prepared by the hydrogen storage material is compounded on the inner wall of the steel pipe by a hot pressing composite process, cooled, polished, and then the outer protective layer formed by the fluorinated plastic is extruded and compounded to the outer wall of the obtained steel pipe by an extruder, cooled, polished, tempered at 160-180° C. for 6-8 hours, and gradually cooled to room temperature;

[0070] S5. Paint spraying

[0071] The hydrogen barrier coating L1 is repeatedly and evenly sprayed onto the inner wall of the pipe obtained in the previous step by a spraying machine until the spraying thickness reaches the required value, and then dried and solidified by hot air at 40-60°C to obtain a finished pipe G;

[0072] S6. Pipeline inspection

[0073] Perform corresponding inspection on the pipeline G through the inspection device, and the technical personnel in this field shall determine the specific inspection items according to the actual needs;

[0074] S7. Packaging and storage

[0075] Qualified pipes that pass the inspection are packed with polyethylene film to avoid dust accumulation and prevent damage during transportation.

[0076] Example 1

[0077] The thickness of hydrogen barrier coating Z-1 is 200μm to 500μm;

[0078] The thickness of the hydrogen storage composite layer C-1 is 4.5 mm;

[0079] Metal tube layer X80, inner diameter φ300, wall thickness 15mm;

[0080] Outer protective layer polytetrafluoroethylene tube 6mm.

[0081] Example 2

[0082] The thickness of hydrogen barrier coating Z-1 is 500 μm;

[0083] The thickness of the hydrogen storage composite layer C-1 is 7.5 mm;

[0084] Metal tube layer: X80, inner diameter φ300, wall thickness 15mm; outer protective layer: polytetrafluoroethylene tube 9mm.

[0085] Example 3

[0086] The thickness of hydrogen barrier coating Z-1 is 250 μm;

[0087] The thickness of the hydrogen storage composite layer C-1 is 6 mm;

[0088] Metal tube layer: X80, inner diameter φ300, wall thickness 15mm; outer protective layer: polytetrafluoroethylene tube 7.5mm.

[0089] Example 4

[0090] The thickness of the hydrogen barrier coating Z-2 is 200μm to 500μm; the thickness of the hydrogen storage composite layer C-2 is 4.5mm;

[0091] Metal tube layer: X80, inner diameter φ300, wall thickness 15mm; outer protective layer: polytetrafluoroethylene tube 6mm.

[0092] Example 5

[0093] The thickness of hydrogen barrier coating Z-2 is 500 μm;

[0094] The thickness of the hydrogen storage composite layer C-2 is 7.5 mm;

[0095] Metal tube layer: X80, inner diameter φ300, wall thickness 15mm; outer protective layer: polytetrafluoroethylene tube 9mm.

[0096] Example 6

[0097] The thickness of hydrogen barrier coating Z-2 is 250 μm;

[0098] The thickness of the hydrogen storage composite layer C-2 is 6 mm;

[0099] Metal tube layer: X80, inner diameter φ300, wall thickness 15mm; outer protective layer: polytetrafluoroethylene tube 7.5mm.

[0100] Example 7

[0101] The thickness of hydrogen barrier coating Z-3 is 200μm to 500μm;

[0102] The thickness of the hydrogen storage composite layer C-3 is 4.5 mm;

[0103] Metal tube layer X80, inner diameter φ300, wall thickness 15mm;

[0104] Outer protective layer polytetrafluoroethylene tube 6mm.

[0105] Example 8

[0106] The thickness of hydrogen barrier coating Z-3 is 500 μm;

[0107] The thickness of the hydrogen storage composite layer C-3 is 7.5 mm;

[0108] Metal tube layer X80, inner diameter φ300, wall thickness 15mm;

[0109] Outer protective layer polytetrafluoroethylene tube 9mm.

[0110] Example 9

[0111] The thickness of hydrogen barrier coating Z-3 is 250 μm;

[0112] The thickness of the hydrogen storage composite layer C-3 is 6 mm;

[0113] Metal tube layer X80, inner diameter φ300, wall thickness 15mm;

[0114] Outer protective layer polytetrafluoroethylene tube 7.5mm.

[0115] After testing, the above pipeline cases were found to have a hydrogen permeability of less than 10% after one year of actual use. -10 mol / m 2 ·s, and it can still maintain normal and stable operation under 40-50Mpa. During the hydrogen desorption test, the difference between the desorption amount and the adsorption amount of the hydrogen storage layer is less than 1%. Therefore, they all have high hydrogen resistance, high pressure resistance, corrosion resistance, hydrogen embrittlement resistance, and can transport hydrogen for a long time.

[0116] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0117] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A composite hydrogen transmission pipeline, characterized in that: The pipeline is provided with a hydrogen barrier coating, a hydrogen storage composite layer, a metal tube layer and an outer protective layer in sequence from the inside to the outside; The hydrogen barrier coating is a composite coating, and its components include 60-70 parts of polytetrafluoroethylene PTFE, 25-35 parts of epoxy resin, 0.8-1.2 parts of crosslinking agent, 5-10 parts of metal oxide filler, 5-10 parts of nitride boron nitride, 3-5 parts of dispersant, 1-2 parts of curing agent, 20-30 parts of cyclohexane, etc. The hydrogen storage composite layer comprises 70-80 parts by weight of polyetheretherketone PEEK, 10-15 parts of fluorinated ethylene propylene copolymer FEP, 2-3 parts of polyethylene wax, 0.5-1 part of polyethyleneimine PEI, 0.2-0.5 part of polyacrylate, 2-3 parts of graphene oxide, 5-10 parts of MOFs material, 4-5 parts of talc powder, and 5-10 parts of triphenylphosphine, a flux reducing agent; The metal tube layer is plated with a metal coating, and the thickness of the coating is 0.3-0.5 mm; The outer protective layer is a tubular structure made of fluorinated plastic.

2. A composite hydrogen transmission pipeline according to claim 1, characterized in that: The thickness of the hydrogen barrier coating is 200 μm to 500 μm.

3. The composite hydrogen transmission pipeline and its preparation process according to claim 1, characterized in that: The ratio of the inner diameter of the metal tube in the metal tube layer to the wall thickness is 20:1, and the metal coating is aluminum coating, nickel coating, titanium coating and molybdenum coating.

4. The composite hydrogen transmission pipeline according to claim 1, characterized in that: The MOFs material used in the hydrogen storage composite layer is ZIF-8 or MOF-5.

5. The composite hydrogen transmission pipeline and its preparation process according to claim 1, characterized in that: The crosslinking agent in the hydrogen barrier coating is tert-butyl peroxide (TBHP), the curing agent is diethylenetriamine, and the dispersant includes 2 to 3 parts of trioctyl phosphate (TPP) and 1 to 2 parts of sodium dodecylbenzene sulfonate.

6. The composite hydrogen transmission pipeline according to claim 1, characterized in that: The fluorinated plastic used in the outer protective layer is one of polytetrafluoroethylene, polyvinylidene fluoride (PVDF) and fluorinated ethylene-propylene copolymer (FEP).

7. The composite hydrogen transmission pipeline according to claim 1, characterized in that: The thickness ratio of the hydrogen storage composite layer to the metal tube layer is 0.3-0.5:

1.

8. The composite hydrogen transmission pipeline according to claim 1, characterized in that: The thickness ratio of the metal tube layer to the outer protective layer is 1:0.4-0.

6.

9. The composite hydrogen transmission pipeline according to claim 1, characterized in that: The metal oxide used in the hydrogen barrier coating is a mixture of one or more of aluminum oxide, titanium oxide, molybdenum oxide and cobalt oxide.

10. A composite hydrogen transmission pipeline according to any one of claims 1 to 9, characterized in that The preparation process comprises the following steps: S1. Material preparation X80 seamless steel pipe; tetrafluoroethylene PTFE, epoxy resin, crosslinking agent tert-butyl peroxide TBHP, metal oxide fillers aluminum oxide, titanium oxide, molybdenum oxide and cobalt oxide, nitride boron nitride, dispersant trioctyl phosphate, polyvinyl alcohol, curing agent diethylenetriamine, cyclohexane; polyetheretherketone PEEK, fluorinated ethylene propylene copolymer FEP, polyethylene wax, polyethyleneimine PEI, polyacrylate, graphene oxide, MOFs material, talc, melting reducer triphenylphosphine; fluorinated plastics polytetrafluoroethylene, polyvinylidene fluoride (PVDF) and fluorinated ethylene-propylene copolymer; S2. Material Pretreatment The hydrogen barrier coating is prepared according to the corresponding mass parts of raw materials used in the formula, mixed evenly, and placed in a container for standby use to obtain coating L1; the raw materials used in the formula are melt-extruded through an extruder to form a hydrogen storage composite layer material pipeline, cooled, polished, and cut into pipelines L2 corresponding to the length of the steel pipe; S3. Pipeline Processing X80 seamless steel pipe surface electroplating 0.3 ~ 0.5mm metal coating S4. Pipeline Composite The surface of the metal-plated X80 seamless steel pipe is sandblasted, a hydrogen storage composite layer is compounded on the inner wall of the steel pipe using the hydrogen storage material L2 through a hot pressing composite process, and then the outer protective layer formed by the fluorinated plastic is compounded on the outer wall of the obtained steel pipe through an extruder, S5. Paint spraying The hydrogen barrier coating L1 is sprayed onto the inner wall of the pipe obtained in the previous step by a spraying machine, and then dried and solidified with hot air at 40-60°C to obtain a finished pipe G; S6. Pipeline inspection Use the detection device to perform corresponding detection on pipeline G. S7. Packaging and storage Qualified pipes that pass the inspection are packed with polyethylene film to avoid dust accumulation and prevent damage during transportation.

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