A polyethylene composite pipe for hydrogen gas transmission and a method for manufacturing the same

Abstract

The application provides a preparation method of a polyethylene composite pipe for conveying hydrogen, and comprises the following steps: step 1: under acidic conditions, a silane coupling agent solution with a mass fraction of 0.5-5% is coated on the outer surface of a cleaned and dried polyethylene pipe and the film surface of an aluminum-plated film respectively, and then baking is performed to obtain a silane coupling agent modified polyethylene pipe and a silane coupling agent modified aluminum-plated film; step 2: after the adhesive is uniformly coated on the film surface of the silane coupling agent modified aluminum-plated film, the silane coupling agent modified aluminum-plated film is uniformly and slowly wound on the outer surface of the silane coupling agent modified polyethylene pipe for 1-5 turns, and then compression baking is performed to obtain the polyethylene composite pipe. The polyethylene pipe for conveying natural gas is used as a base material, and after surface modification, the polyethylene pipe is adhered and combined with the aluminum-plated film after surface modification through an adhesive to prepare the polyethylene composite pipe with excellent gas barrier property.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen transmission pipes, and specifically relates to a polyethylene composite pipe for transporting hydrogen and its preparation method. Background Technology

[0002] Hydrogen energy, as a renewable secondary energy source, boasts advantages such as cleanliness, environmental friendliness, diverse sources, and convenient storage and transportation, making it one of the most promising clean energy sources in the 21st century. Currently, many countries consider hydrogen energy development a crucial energy strategy. Hydrogen transportation is a vital link in hydrogen energy utilization, and safe and efficient hydrogen transportation technology is a prerequisite for the large-scale commercial development of hydrogen energy. Based on the state of hydrogen during transportation, it can be categorized into gaseous hydrogen transportation, liquid hydrogen transportation, and solid-state hydrogen transportation, with gaseous hydrogen transportation being the most mature method at present. Depending on the transportation distance, hydrogen usage requirements, and user distribution, hydrogen can be transported via hydrogen pipelines and long-tube trailers. For applications involving large volumes and long distances, pipeline transportation is the most efficient method.

[0003] Hydrogen pipelines can be divided into long-distance transmission pipelines and short-distance distribution pipelines. Long-distance pipelines transport hydrogen at higher pressures and with larger diameters, primarily used for the long-distance, large-scale transportation of high-pressure hydrogen between hydrogen production units and hydrogen stations. Distribution pipelines transport hydrogen at lower pressures and with smaller diameters, mainly used for the distribution of medium- and low-pressure hydrogen between hydrogen stations and individual users. my country's hydrogen transmission system construction is relatively lagging, with the total length of existing hydrogen transmission pipelines only about 400 km. Currently, hydrogen transmission pipelines mostly use seamless steel pipes, primarily made of low-strength pipeline steels such as X42, X52, and X56. This results in limited transmission pressure, thick pipe walls, low transmission efficiency, and high construction costs, further restricting the large-scale use of hydrogen energy. In recent years, extensive research has been conducted abroad on cost reduction and efficiency improvement for hydrogen pipeline systems. On the one hand, efforts are being made to develop new materials, such as fiber composite materials, for hydrogen transmission to reduce pipeline construction costs. On the other hand, performance characterization and evaluation studies are being conducted on traditional pipe materials, such as high-strength steel, to reveal the influence of different pressures and load frequencies on the pipe body and welds.

[0004] Traditional seamless steel pipes suffer from hydrogen embrittlement during hydrogen transportation, gradually forming tiny cracks within the steel and posing serious safety hazards. While polymer pipes, such as polyethylene pipes commonly used for natural gas transportation, do not experience hydrogen embrittlement and are inexpensive, their high molecular spacing after processing results in high hydrogen permeability, limiting their large-scale use in hydrogen transportation. Summary of the Invention

[0005] This invention addresses the technical problems existing in the prior art by providing a polyethylene composite pipe for transporting hydrogen and its preparation method. Using a polyethylene pipe for transporting natural gas as the base material, after surface modification, it is bonded and composited with a surface-modified aluminum-coated film using an adhesive to prepare a polyethylene composite pipe with excellent gas barrier properties.

[0006] The technical solution adopted in this invention is: a method for preparing a polyethylene composite pipe for transporting hydrogen, comprising the following steps:

[0007] Step 1: The polyethylene pipe and the aluminized film are thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence and then dried. Under acidic conditions, a 0.5-5% (w / w) silane coupling agent solution is coated onto the cleaned and dried outer surface of the polyethylene pipe and the film surface of the aluminized film, respectively, and then dried to obtain silane coupling agent modified polyethylene pipe and silane coupling agent modified aluminized film.

[0008] Step 2: After uniformly coating the adhesive onto the aluminum-coated film modified with silane coupling agent, wrap it around the outer surface of the polyethylene pipe modified with silane coupling agent 1 to 5 times at a uniform speed and slowly. After pressing and drying, the polyethylene composite pipe is obtained.

[0009] Furthermore, the polyethylene pipe is a special polyethylene pipe for transporting natural gas, and the raw material grade is PE100.

[0010] Furthermore, the aluminized film is a polyester aluminized film or a cast polypropylene aluminized film.

[0011] Furthermore, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0012] Furthermore, the solvent of the silane coupling agent solution is one or more of water, methanol, and ethanol.

[0013] Furthermore, the pH of the acidic conditions is 3.5 to 5.5, provided by acetic acid.

[0014] Furthermore, the adhesive is one or more of epoxy resin adhesives, polyurethane adhesives, and polyvinyl acetate adhesives.

[0015] Furthermore, the ratio of the adhesive to the silane coupling agent modified aluminum-coated film is 50–200 g / m. 2 .

[0016] Furthermore, the drying temperature is 30–70°C, and the drying time is 1–4 hours.

[0017] The technical solution adopted in this invention is: a polyethylene composite pipe prepared by a method for transporting hydrogen.

[0018] Compared with the prior art, the beneficial effects of this invention are as follows: This invention uses a silane coupling agent solution with a mass fraction of 0.5-5% as a modifier to modify the surface of polyethylene pipes for transporting natural gas and aluminized films. The two are then bonded together with an adhesive to prepare a polyethylene composite pipe with excellent gas barrier properties, achieving a hydrogen permeability of 0.01-0.02 cm⁻¹. 3 / m 2 24h. The process of this invention is simple, can improve the hydrogen barrier performance of existing polyethylene pipes for transporting natural gas, and has low production costs. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to specific embodiments. The polyethylene pipe used in the embodiments of the present invention is a special polyethylene pipe for transporting natural gas, with a raw material grade of PE100 and a pipe size of 32mm (diameter) × 3mm (wall thickness). The manufacturer is Asia Pacific Group. The aluminized film is a polyester aluminized film and a cast polypropylene aluminized film, manufactured by Jiaxing Pengxiang Packaging Materials Co., Ltd. Example 1

[0020] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0021] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 1% γ-glycidyl etheroxypropyltrimethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in a 60℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0022] Step 2: Take 1m 2 The silane coupling agent modified polyester aluminized film is prepared by uniformly coating 100g of epoxy resin adhesive onto the surface of the aluminized film, and then slowly and evenly wrapping it around the outer surface of the silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, it is pressed and dried in a 60℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0023] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0024] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.01 cm³. 3 / m 2 24 hours. Example 2

[0025] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0026] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 5% γ-glycidyl etheroxypropyltrimethoxysilane to adjust the pH to 4. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in a 60℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0027] Step 2: Take 1m 2 A silane coupling agent modified polyester aluminized film is prepared by uniformly coating 100g of polyurethane adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 60℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0028] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0029] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.02 cm³. 3 / m 2 24 hours. Example 3

[0030] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0031] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of an ethanol solution of 2% γ-aminopropyltriethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the film surface of the cast polypropylene aluminized film. After drying in a 60℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and the cast polypropylene aluminized film were obtained.

[0032] Step 2: Take 1m 2 A silane coupling agent modified cast polypropylene aluminized film is prepared by uniformly coating 100g of epoxy resin adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 60℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0033] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0034] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.02 cm³. 3 / m 2 24 hours. Example 4

[0035] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0036] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 1% γ-methacryloxypropyltrimethoxysilane to adjust the pH to 3.5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in a 60℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0037] Step 2: Take 1m 2The silane coupling agent modified polyester aluminized film is prepared by uniformly coating 50g of polyvinyl acetate adhesive onto the surface of the aluminized film, then wrapping it around the outer surface of the silane coupling agent modified polyethylene pipe three times at a uniform speed and slowly. After trimming and finishing, it is pressed and dried in a 60℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0038] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0039] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.02 cm³. 3 / m 2 24 hours. Example 5

[0040] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0041] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 0.5% γ-glycidyl etheroxypropyltrimethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the cast polypropylene aluminized film. After drying in a 60℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and the cast polypropylene aluminized film were obtained.

[0042] Step 2: Take 1m 2 A silane coupling agent modified cast polypropylene aluminized film is produced by uniformly coating 200g of polyurethane adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 50℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0043] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0044] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.01 cm³. 3 / m 2 24 hours. Example 6

[0045] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0046] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of an aqueous solution of 2.5% γ-glycidyl etheroxypropyltrimethoxysilane to adjust the pH to 5.5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in an oven at 40℃ to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0047] Step 2: Take 1m 2 A silane coupling agent modified polyester aluminized film is prepared by uniformly coating 100g of polyvinyl acetate adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 50℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0048] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0049] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.02 cm³. 3 / m 2 24 hours. Example 7

[0050] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0051] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 1.0% γ-methacryloyloxypropyltrimethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in an oven at 50℃ to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0052] Step 2: Take 1m 2 A silane coupling agent modified polyester aluminized film is prepared by uniformly coating 150g of polyurethane adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 50℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0053] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0054] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.01 cm³. 3 / m 2 24 hours. Example 8

[0055] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0056] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of an ethanol solution of 2.0% γ-aminopropyltriethoxysilane to adjust the pH to 4. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the film surface of the cast polypropylene aluminized film. After drying in a 50℃ oven to constant weight, the silane coupling agent modified polyethylene pipe and the cast polypropylene aluminized film were obtained.

[0057] Step 2: Take 1m 2A silane coupling agent modified cast polypropylene aluminized film is prepared by uniformly coating 100g of epoxy resin adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 40℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0058] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0059] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.01 cm³. 3 / m 2 24 hours. Example 9

[0060] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0061] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of a methanol solution of 1.0% γ-glycidyl etheroxypropyltrimethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in an oven at 50℃ to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0062] Step 2: Take 1m 2 A silane coupling agent modified polyester aluminized film is prepared by uniformly coating 120g of polyurethane adhesive onto the surface of the aluminized film, then slowly and evenly wrapping it around the outer surface of a silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, the film is pressed and dried in a 30℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0063] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0064] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.02 cm³. 3 / m 2 24 hours. Example 10

[0065] An embodiment of the present invention provides a method for preparing a polyethylene composite pipe for transporting hydrogen, which includes the following steps:

[0066] Step 1: The polyethylene pipe and the aluminized film were thoroughly cleaned with distilled water, anhydrous ethanol, and distilled water in sequence, and then dried. Acetic acid was added to 100g of an ethanol solution of 1.0% γ-aminopropyltriethoxysilane to adjust the pH to 5. After stirring for 5 minutes, the silane coupling agent solution was uniformly coated onto the outer surface of the polyethylene pipe and the surface of the polyester aluminized film. After drying in an oven at 40℃ to constant weight, the silane coupling agent modified polyethylene pipe and polyester aluminized film were obtained.

[0067] Step 2: Take 1m 2 The silane coupling agent modified polyester aluminized film is prepared by uniformly coating 200g of epoxy resin adhesive onto the surface of the aluminized film, and then slowly and evenly wrapping it around the outer surface of the silane coupling agent modified polyethylene pipe for 3 turns. After trimming and finishing, it is pressed and dried in a 70℃ oven to constant weight, resulting in a polyethylene composite pipe with excellent gas barrier properties that can be used to transport hydrogen.

[0068] Hydrogen permeability test: The hydrogen permeability of the composite pipe was measured using a hydrogen barrier tester at a pressure of 0.1 MPa for 24 hours. This process was repeated three times, and the average value was taken as the hydrogen permeability of the polyethylene composite pipe.

[0069] Trimmed polyethylene composite pipe was placed in a hydrogen barrier property testing device. After sealing, the hydrogen valve was opened and pressurized to 0.1 MPa, then pressurization was stopped. After 24 hours, the pressure change in the testing device was recorded. Calculations showed that the hydrogen permeability of the polyethylene composite pipe was 0.01 cm³. 3 / m 2 24 hours.

[0070] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of the present invention. The scope of protection of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and protection scope of the present invention, to achieve the above-mentioned technical effects, or any equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention.

Claims

1. A method for preparing a polyethylene composite pipe for transporting hydrogen, characterized in that: Includes the following steps: Step 1: Under acidic conditions with a pH of 3.5–5.5, a 0.5–5% (w / w) silane coupling agent solution is coated onto the outer surface of a polyethylene pipe and the surface of an aluminized film, respectively. The coated film is then dried at 30–70°C for 1–4 hours to obtain silane coupling agent-modified polyethylene pipe and silane coupling agent-modified aluminized film. The polyethylene pipe is a PE100 grade polyethylene pipe specifically for transporting natural gas. The aluminized film is a polyester aluminized film or a cast polypropylene aluminized film. The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane. Step 2: After uniformly coating the adhesive onto the surface of the silane coupling agent modified aluminized film, wrap it slowly and evenly around the outer surface of the silane coupling agent modified polyethylene pipe for 1 to 5 turns. The ratio of adhesive to silane coupling agent modified aluminized film is 50 to 200 g / m. 2 After being compressed and dried to constant weight, polyethylene composite pipes were obtained. The hydrogen permeability of the obtained polyethylene composite pipes under conditions of 0.1 MPa and 24 h was 0.01–0.02 cm⁻¹. 3 / m 2 ·24h.

2. The method for preparing the polyethylene composite pipe for hydrogen delivery as described in claim 1, characterized in that: Before S1, the special polyethylene pipe for transporting natural gas and the aluminized film are cleaned in sequence with distilled water, anhydrous ethanol, and distilled water, and then dried.

3. The method for preparing the polyethylene composite pipe for hydrogen delivery as described in claim 1, characterized in that: The solvent for the silane coupling agent solution is one or more of water, methanol, and ethanol.

4. The method for preparing the polyethylene composite pipe for hydrogen delivery as described in claim 1, characterized in that: The adhesive is one or more of epoxy resin adhesives, polyurethane adhesives, and polyvinyl acetate adhesives.

5. A polyethylene composite pipe for transporting hydrogen, characterized in that: The composite pipe for transporting hydrogen is prepared using the method described in any one of claims 1-4. It comprises a PE100 polyethylene pipe substrate for transporting natural gas and an aluminized film barrier layer disposed on the outer surface of the substrate. The aluminized film barrier layer is bonded to the substrate by an adhesive. Both the outer surface of the substrate and the surface of the aluminized film are modified with a silane coupling agent. The aluminized film barrier layer is formed by winding a polyester aluminized film or a cast polypropylene aluminized film 1-5 times around the outer surface of the substrate. The hydrogen permeability of the composite pipe under 0.1 MPa and 24h conditions is 0.01–0.02 cm⁻¹. 3 / m 2 ·24h.