Hydrogen transport resin composite pipe

Abstract

To provide a hydrogen transport resin composite pipe that has flexibility as a resin pipe while exhibiting superior hydrogen permeation resistance and pressure resistance.SOLUTION: A hydrogen transport resin composite pipe comprises: a resin inner pipe; a first reinforcing layer made of aluminum that covers the outer peripheral surface of the inner pipe; a second reinforcing layer made of a unidirectional fiber-reinforced thermoplastic composite material that covers the outer surface of the first reinforcing layer; and a corrosion-resistant layer covering the outer surface of the second reinforcing layer, the corrosion-resistant layer comprising at least one resin selected from the group consisting of vinyl chloride resin, epoxy resin, polyethylene resin, urethane resin, and fluororesin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a composite resin pipe for transporting hydrogen. [Background technology]

[0002] Hydrogen is expected to become a clean energy source, and its use is expected to expand in the future. For example, in Japan, as hydrogen stations and other facilities become more established, consideration is being given to establishing local hydrogen networks that supply hydrogen from hydrogen stations in coastal areas to local transport within a certain area, from production to use.

[0003] Pipelines are a leading candidate for transporting hydrogen, both in terms of cost and environmental friendliness, and consideration is underway both domestically and internationally. In Europe, there is a movement to utilize gas pipelines for hydrogen transportation, and polyethylene piping, which is standardized for transporting city gas (methane gas), is being used for hydrogen supply because it can be directly buried. In this case, although the amount of hydrogen gas that permeates through the piping is greater than that of methane gas, the combustion energy is assessed as equivalent to that of methane gas, and this risk assessment is based on the fact that hydrogen gas that permeates through buried piping is unlikely to disperse into the soil and become locally concentrated.

[0004] In Japan, the cost of laying hydrogen pipelines (particularly burying them) is high, posing economic challenges. Therefore, there is a movement to utilize existing underground infrastructure, such as communication cable piping, water and sewerage systems, and utility tunnels, for hydrogen pipelines (see Non-Patent Document 1). In this case, unlike the direct burial described above, the pipes must have the following performance characteristics: 1) flexibility, allowing them to be laid from above ground through manholes into existing pipes, and 2) the ability to reduce the amount of hydrogen permeating from the pipes in closed spaces so that hydrogen does not become highly concentrated. Non-Patent Document 1 therefore considers the use of flexible pipes made of stainless steel.

[0005] Patent Document 1 (JP 2023-148911 A) discloses a hydrogen supply facility that aims to improve safety in supplying hydrogen through a conduit. This hydrogen supply facility includes a conduit that is buried and extends underground, a cladding pipe that covers the outer periphery of the conduit, branch pipes branching off from the cladding pipe, and a sensor that can detect hydrogen. This document states that the conduit (pipeline) and cladding pipe (cover) can be steel pipes made of stainless steel, carbon steel, or the like, or plastic pipes made of polyethylene, polyvinyl chloride, or the like.

[0006] Patent Document 2 (JP 2007-283582 A) discloses a multilayer resin pipe for hydrogen supply that combines hydrogen gas barrier properties with the mechanical strength of a molded article. This multilayer resin pipe for hydrogen supply includes at least five layers consisting of a polyolefin layer (outer layer), an adhesive layer, a gas barrier layer, another adhesive layer, and a polyolefin layer (inner layer), and has a hydrogen gas barrier capacity of 1000 cc / m 2 It exhibits a hydrogen permeation rate of less than 1000kJ / day atm.

[0007] Patent Document 3 (JP 2023-547754 A) discloses a multilayer structure for storing or transporting hydrogen-containing gases, which has improved hydrogen barrier properties. This multilayer structure includes at least three layers, including an inner layer containing at least one first polymer, a middle layer containing an ethylene-vinyl alcohol copolymer, and an outer layer containing at least one second polymer. In this multilayer structure, the water vapor transmission rate of the inner layer is lower than that of the outer layer.

[0008] Non-Patent Document 2 (RJM Hermkens, H. Colmer and HA Ophoff, "MODERN PE PIPE ENABLES THE TRANSPORT OF HYDROGEN") investigates the permeation rate of hydrogen through polyethylene pipes to investigate the suitability of polyethylene pipes for the transportation of hydrogen in specific industrial sites. This document shows the permeation behavior of a certain polyethylene pipe and also reports that the permeability coefficient (PC) of the polyethylene pipe is 126.8 (ml·mm) / (m 2It is stated that the date was ·day·bara). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2023-148911 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-283582 [Patent Document 3] Special Publication No. 2023-547754 [Non-patent literature]

[0010] [Non-Patent Document 1] Ryo Matsuki, "Ultra-High Pressure Hydrogen Infrastructure Full-Scale Dissemination Technology Research and Development Project / Research and Development on International Expansion, International Standardization, etc. / Study on Technical Standards Related to Hydrogen Supply Infrastructure," NEDO Hydrogen and Fuel Cell Results Report 2023, Presentation No. B1-6, July 13, 2023 (Available at the URL: https: / / hydrogen2023.nedo.go.jp / wp-content / uploads / 2023 / 06 / B1-6.pdf) [Non-patent document 2] RJM Hermkens, H. Colmer and HA Ophoff, "MODERN PE PIPE ENABLES THE TRANSPORT OF HYDROGEN" Proceedings of the 19th Plastic Pipes Conference PPXIX September 24-26, 2018, Las Vegas, Nevada, pp. 1-11 Summary of the Invention

[0011] In Japan, there are various restrictions, such as laws and regulations, regarding piping for flammable gases, and no development has yet been made for hydrogen transportation. The use of metal pipes as hydrogen transportation piping has been proposed or considered, but this increases construction costs and poses the problem of hydrogen embrittlement. Additionally, the stainless steel flexible pipes discussed in Non-Patent Document 1 have drawbacks, such as difficulty in inserting them into existing piping due to limited flexibility, the inability to manufacture them in long lengths, and the high cost of the pipes themselves, resulting in a lack of versatility. Therefore, there is a need for hydrogen transportation piping that is flexible yet exhibits excellent hydrogen permeation resistance.

[0012] The present inventors have now discovered that by sequentially laminating a first reinforcing layer made of aluminum, a second reinforcing layer made of a unidirectional fiber-reinforced thermoplastic composite material, and a corrosion-resistant layer containing a specified resin on a resin inner tube, it is possible to provide a resin composite pipe for transporting hydrogen that has the flexibility of a resin pipe but also has excellent hydrogen permeation resistance and pressure resistance.

[0013] Therefore, an object of the present invention is to provide a composite resin pipe for transporting hydrogen which has flexibility as a resin pipe, but also has excellent resistance to hydrogen permeation and pressure resistance.

[0014] According to the present disclosure, the following aspects are provided. [Aspect 1] A composite resin pipe for transporting hydrogen, A resin inner tube; a first reinforcing layer made of aluminum covering an outer peripheral surface of the inner pipe; A second reinforcing layer made of a unidirectional fiber-reinforced thermoplastic composite material covering the outer surface of the first reinforcing layer; a corrosion protection layer covering an outer surface of the second reinforcing layer and including at least one resin selected from the group consisting of vinyl chloride resin, epoxy resin, polyethylene resin, urethane resin, and fluorine-based resin; A composite resin pipe for transporting hydrogen, comprising: [Aspect 2] 2. The composite resin pipe for transporting hydrogen according to claim 1, wherein the resin constituting the inner pipe includes polyethylene or polyamide. [Aspect 3] 3. The composite resin pipe for transporting hydrogen according to claim 1, wherein the resin constituting the inner pipe is high-density polyethylene. [Aspect 4] A resin composite pipe for transporting hydrogen according to any one of aspects 1 to 3, wherein the unidirectional fiber-reinforced thermoplastic composite material comprises glass fibers oriented in one direction and a polyethylene terephthalate (PET) resin impregnated into the glass fibers. [Aspect 5] Aspect 5. The composite resin pipe for transporting hydrogen according to aspect 4, wherein the polyethylene terephthalate (PET) resin is an amorphous polyethylene terephthalate (A-PET) resin. [Aspect 6] A composite resin pipe for transporting hydrogen according to any one of aspects 1 to 5, wherein the first reinforcing layer and the second reinforcing layer are provided by a reinforcing tape including the first reinforcing layer and the second reinforcing layer. [Aspect 7] 7. The composite resin pipe for transporting hydrogen according to any one of Aspects 1 to 6, wherein the anticorrosion layer contains a low-density polyethylene resin or a vinyl chloride resin. [Aspect 8] A composite resin pipe for transporting hydrogen according to any one of Aspects 1 to 7, wherein the thickness of the inner pipe is 3.0 mm or more and 13.0 mm or less. [Aspect 9] A composite resin pipe for transporting hydrogen according to any one of Aspects 1 to 8, wherein the first reinforcing layer has a thickness of 0.01 mm or more and 0.5 mm or less. [Aspect 10] 10. The composite resin pipe for transporting hydrogen according to any one of Aspects 1 to 9, wherein the second reinforcing layer has a thickness of 0.1 mm or more and 1.0 mm or less. [Aspect 11] 11. The composite resin pipe for transporting hydrogen according to any one of Aspects 1 to 10, wherein the anticorrosion layer has a thickness of 1.0 mm or more and 3.0 mm or less. [Aspect 12] 12. A resin composite pipe for hydrogen transport according to any one of aspects 1 to 11, wherein the inner diameter of the resin composite pipe for hydrogen transport is 35.0 mm or more and 120.0 mm or less, and the outer diameter of the resin composite pipe for hydrogen transport is 40.0 mm or more and 130.0 mm or less. [Aspect 13] 13. The composite resin pipe for transporting hydrogen according to any one of aspects 1 to 12, further comprising a nonwoven fabric between the inner pipe and the first reinforcing layer, the nonwoven fabric covering an outer peripheral surface of the inner pipe. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view schematically showing an example of a composite resin pipe for transporting hydrogen. [Figure 2] FIG. 1 is a perspective view schematically showing an example of a resin composite pipe for transporting hydrogen. [Figure 3] FIG. 10 is a diagram illustrating an example of how to wrap a reinforcing tape around an inner pipe (two layers with a 1 / 3 gap). [Figure 4] 1 is a photograph showing test specimens for hydrogen permeation testing prepared in Examples 1 and 2. [Figure 5] FIG. 1 is a conceptual diagram of a measurement device equipped with a piping flow used in Examples 1 and 2. [Figure 6] 1 shows a test waveform of a hydrogen permeation test obtained for a test specimen of Example 1. [Figure 7] 1 is a test waveform of a hydrogen permeation test obtained for the test specimen of Example 2. [Figure 8] 1 is a graph showing the change over time in the amount of hydrogen permeation per unit length measured for the test specimens of Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] FIG. 1 shows an example of a composite resin pipe 10 for hydrogen transport according to the present invention. The composite resin pipe 10 for hydrogen transport includes an inner pipe 12, a first reinforcing layer 14, a second reinforcing layer 16, and a corrosion-resistant layer 18. The inner pipe 12 is a resin pipe. The first reinforcing layer 14 is an aluminum layer that covers the outer surface of the inner pipe 12. The second reinforcing layer 16 is a layer that covers the outer surface of the first reinforcing layer 14 and is made of a unidirectional fiber-reinforced thermoplastic composite material. The corrosion-resistant layer 18 is a layer that covers the outer surface of the second reinforcing layer 16 and contains at least one resin selected from the group consisting of vinyl chloride resin, epoxy resin, polyethylene resin, urethane resin, and fluorine-based resin. A nonwoven fabric 20 may further be provided between the inner pipe 12 and the first reinforcing layer 14. In this way, by sequentially laminating a nonwoven fabric 20, an aluminum first reinforcing layer 14, a unidirectional fiber-reinforced thermoplastic composite second reinforcing layer 16, and a corrosion-resistant layer 18 containing a specified resin on a resin inner pipe 12, it is possible to provide a composite resin pipe 10 for transporting hydrogen that has the flexibility of a resin pipe but also has excellent hydrogen permeation resistance and pressure resistance.

[0017] The advantages of the composite resin pipe 10 for hydrogen transport can be explained as follows. First, by using a resin pipe for the inner pipe 12, the composite resin pipe 10 for hydrogen transport can be given the flexibility of a resin pipe. Second, the combination of the first reinforcing layer 14 made of aluminum and the second reinforcing layer 16 made of a unidirectional fiber-reinforced thermoplastic composite material can impart excellent hydrogen permeation resistance and pressure resistance to the flexible inner pipe 12. Furthermore, the presence of the corrosion-resistant layer 18 as the outermost layer can protect the inner pipe 12, the first reinforcing layer 14, and the second reinforcing layer 16 from external factors (damage, abrasion, corrosion, ultraviolet degradation, etc.), allowing the composite resin pipe 10 for hydrogen transport to maintain its intended functions for a long period of time.

[0018] As mentioned above, there is a movement in Japan to utilize existing underground infrastructure, such as communication cable piping, water supply and sewerage systems, and utility conduits, for hydrogen pipelines (see Non-Patent Document 1). In this case, hydrogen transport piping is required to have the following characteristics: 1) flexibility for laying the pipe from above ground through a manhole into an existing pipe; and 2) reducing the amount of hydrogen permeation so that hydrogen permeating from the pipe does not become highly concentrated in a closed space. The composite resin pipe 10 for hydrogen transport of the present invention is an extremely promising candidate for such applications. From this perspective, the composite resin pipe 10 for hydrogen transport preferably has a size suitable for existing underground infrastructure, such as communication cable piping, water supply and sewerage systems, and utility conduits. Specifically, the inner diameter of the composite resin pipe 10 for hydrogen transport is preferably 35.0 mm or more and 120.0 mm or less, more preferably 35.0 mm or more and 80.0 mm or less, and even more preferably 40.0 mm or more and 60.0 mm or less. The outer diameter of the composite resin pipe 10 for transporting hydrogen is preferably 40.0 mm or more and 130.0 mm or less, more preferably 40.0 mm or more and 100.0 mm or less, and even more preferably 50.0 mm or more and 65.0 mm or less.

[0019] The inner pipe 12 is a pipe made of resin. The resin constituting the inner pipe 12 preferably contains polyethylene or polyamide, and more preferably contains polyethylene. A pipe made of high-density polyethylene (HDPE) is particularly preferred, and a typical example is a high-density polyethylene pipe using PE100 conforming to ISO 4427-1:2019 and ISO 4427-2:2019. ISO 4427-1 and ISO 4427-2 are international standards corresponding to polyethylene pipe standards in Japan, such as JIS and JWWA. PE100 is a high-density polyethylene classified as PE100 in the ISO 9080 extrapolation method and the ISO 12162 classification table. Thus, a commercially available single-layer pipe made of high-density polyethylene can be used as the inner pipe 12. The inner pipe 12 made of the above-mentioned resin is flexible, allowing it to be bent while being laid, can be used on soft ground, and has excellent earthquake resistance. Therefore, similar to the above, flexibility can be utilized in a manner similar to that described above, even when other layers are laminated on the inner pipe 12 to form the composite resin pipe for transporting hydrogen 10. The thickness of the inner pipe 12 is preferably 3.0 mm or more and 13.0 mm or less, more preferably 3.0 mm or more and 10.0 mm or less, and even more preferably 3.5 mm or more and 6.5 mm or less.

[0020] The first reinforcing layer 14 covers the outer peripheral surface of the inner pipe 12, and together with the second reinforcing layer 16, contributes to improving hydrogen permeation resistance and pressure resistance. The first reinforcing layer 14 is made of aluminum. The thickness of the first reinforcing layer 14 is preferably 0.01 mm or more and 0.5 mm or less, more preferably 0.01 mm or more and 0.25 mm or less, and even more preferably 0.05 mm or more and 0.15 mm or less. Therefore, commercially available aluminum foil or aluminum sheet can be used as the first reinforcing layer 14. The first reinforcing layer 14 may be made of an alloy containing aluminum, as long as the effects of the present invention are not impaired.

[0021] The second reinforcing layer 16 covers the outer surface of the first reinforcing layer 14, thereby contributing to improving hydrogen permeation resistance and pressure resistance together with the first reinforcing layer 14. The second reinforcing layer 16 is composed of a unidirectional fiber-reinforced thermoplastic composite material. A unidirectional fiber-reinforced thermoplastic composite material is a type of continuous fiber-reinforced thermoplastic composite material, known as a composite material in which all fibers are aligned in one direction within a resin matrix. Unidirectional fiber-reinforced thermoplastic composite materials are typically commercially available in the form of tape, and such tapes are called UD tape, uni-tape, or uni. Unidirectional fiber-reinforced thermoplastic composite materials exhibit excellent strength and elastic modulus in that direction because all of their fibers are aligned in one direction. Preferred examples of fibers contained in unidirectional fiber-reinforced thermoplastic composites include glass fiber and carbon fiber, with glass fiber being more preferred. Examples of matrix resins impregnated into the fibers include high-density polyethylene (HDPE), nylon 6, nylon 66, polypropylene (PP), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyethylene terephthalate (PET), with polyethylene terephthalate (PET) being particularly preferred. A preferred unidirectional fiber-reinforced thermoplastic composite material contains unidirectionally oriented glass fibers and a polyethylene terephthalate (PET) resin impregnated into the glass fibers. In particular, the polyethylene terephthalate (PET) resin is preferably amorphous polyethylene terephthalate (A-PET) resin. A preferred product example of a unidirectional fiber-reinforced thermoplastic composite material containing glass fibers and amorphous polyethylene terephthalate (A-PET) resin is Polystrand manufactured by Avient. TM The thickness of the second reinforcing layer 16 is preferably 0.1 mm or more and 1.0 mm or less, more preferably 0.1 mm or more and 0.7 mm or less, and even more preferably 0.1 mm or more and 0.3 mm or less.

[0022] The first reinforcing layer 14 and the second reinforcing layer 16 are preferably provided by a reinforcing tape 17 including the first reinforcing layer 14 and the second reinforcing layer 16. In the form of the reinforcing tape 17, by wrapping the reinforcing tape 17 around the inner pipe 12, it is possible to easily impart improved hydrogen permeation resistance and pressure resistance to the inner pipe 12 while maintaining the flexibility of the inner pipe 12. Therefore, by utilizing a commercially available or existing inner pipe 12 such as a polyethylene pipe, it is possible to produce a high-performance composite resin pipe for hydrogen transport 10 with few steps and at low cost.

[0023] The method for winding the reinforcing tape 17 around the inner pipe 12 (or the inner pipe 12 covered with the nonwoven fabric 20) is not particularly limited, and can be performed by various known methods. A preferred example is a method in which, assuming the width of the reinforcing tape 17 is L, a first layer of reinforcing tape 17 is wound around the inner pipe 12 while leaving a gap of L / 3, as shown in FIG. 3( a), and then a second layer of reinforcing tape 17 is wound around the inner pipe 12 so as to close the gap of L / 3 at the center in the width direction (i.e., so that both sides of the gap overlap with the first layer of reinforcing tape 17 by a width of L / 3), as shown in FIG. 3( b) (hereinafter referred to as "two-layer winding with a gap of 1 / 3"). Note that while the reinforcing tape 17 itself includes a two-layer structure consisting of the first reinforcing layer 14 and the second reinforcing layer 16, the first or second reinforcing tape 17 referred to here refers to the reinforcing tape 17 (i.e., the combination of the first reinforcing layer 14 and the second reinforcing layer 16) as being a single layer. The two-layer winding with a 1 / 3 gap makes it relatively easy to wind the reinforcing tape 17 around the inner pipe 12, and also allows the outer peripheral surface of the inner pipe 12 to be covered without any gaps with at least one layer of reinforcing tape 17. Furthermore, because there is a portion D where the reinforcing tape 17 is double-wrapped with a width of L / 3, when the composite pipe 10 is bent or stretched, the reinforcing tape 17 in the double-wrapped portion D shifts slightly, allowing the composite pipe 10 to maintain a state where it is covered with at least one layer of reinforcing tape 17.

[0024] The corrosion-resistant layer 18 covers the outer surface of the second reinforcing layer 16, thereby protecting the inner pipe 12, the first reinforcing layer 14, and the second reinforcing layer 16 from external factors (damage, abrasion, corrosion, UV degradation, etc.). The corrosion-resistant layer 18 preferably contains at least one resin selected from the group consisting of vinyl chloride resin, epoxy resin, polyethylene resin, urethane resin, and fluorine-based resin, and more preferably contains low-density polyethylene resin (LDPE) or vinyl chloride resin. Using such a resin allows the corrosion-resistant layer 18 to easily conform to the shape of the composite pipe 10 and ensures sufficient protection from external factors. Furthermore, the corrosion-resistant layer 18 may be made of a black resin, such as polyethylene resin with added carbon, from the perspective of weather resistance, as is done for the coating of electric wires, etc. The thickness of the corrosion-resistant layer 18 is preferably 1.0 mm to 3.0 mm, more preferably 1.0 mm to 2.0 mm, and even more preferably 1.2 mm to 1.5 mm.

[0025] If desired, a nonwoven fabric 20 may be provided between the inner tube 12 and the first reinforcing layer 14 so as to cover the outer peripheral surface of the inner tube 12. Interposing the nonwoven fabric 20 between the inner tube 12 and the first reinforcing layer 14 has the advantage of reducing frictional resistance between the inner tube 12 and the first reinforcing layer 14. Commercially available nonwoven fabrics can be used as the nonwoven fabric 20, but synthetic fiber nonwoven fabrics are preferred. Synthetic fiber nonwoven fabrics can be manufactured by known methods such as meltblowing, spunbonding, and needlepunching. The synthetic fiber nonwoven fabric is preferably made of a thermoplastic resin. Examples of thermoplastic resins include polyamide, polyester, polypropylene, and polyethylene. The thickness of the nonwoven fabric 20 is preferably 0.1 mm to 0.5 mm, more preferably 0.1 mm to 0.3 mm, and even more preferably 0.1 mm to 0.2 mm. [Example]

[0026] The present invention will be explained in more detail by the following examples, but the present invention is not limited to the following examples.

[0027] Examples 1 and 2 (1) Fabrication of composite resin pipe for hydrogen transport In each example, the following materials were prepared: Inner pipe 12: High-density polyethylene pipe (Mitsui Metals Engineering Co., Ltd., WED-13.6, nominal diameter: W50, minimum outer diameter: 63.0 mm, maximum outer diameter: 63.4 mm, minimum thickness: 4.7 mm, maximum thickness: 5.3 mm) Nonwoven fabric 20: Polyester nonwoven fabric (manufactured by Toyobo MC Co., Ltd., product name: Polyester spunbond ECULE (registered trademark), thickness: 0.19 mm) Reinforcing tape 17: A tape having a two-layer structure of a first reinforcing layer 14 and a second reinforcing layer 16 shown below (thickness: 0.2835 mm (Example 1) or 0.347 mm (Example 2)) First reinforcing layer 14: Aluminum layer (thickness: 0.0635 mm (Example 1) or 0.127 mm (Example 2)) Second reinforcing layer 16: Unidirectional Fiberglass Reinforced Thermoplastic Tape (Avient, Polystrand) containing glass fibers impregnated with amorphous polyethylene terephthalate (A-PET) resin TM aPET5848 (IE5848U), thickness: 0.22 mm (Examples 1 and 2) Anti-corrosion layer 18: Low-density polyethylene (LDPE) colored black with carbon additives

[0028] The nonwoven fabric 20 was tightly wrapped around the inner pipe 12, covering the outer surface of the inner pipe 12 with the nonwoven fabric 20. The reinforcing tape 17 was then wrapped around the inner pipe 12 covered with the nonwoven fabric 20 using the "two-layer wrap with a 1 / 3 gap" method described above, so that the first reinforcing layer 14 was in contact with the nonwoven fabric 20. A corrosion-resistant layer 18 (minimum thickness: 1.2 mm, maximum thickness: 2.1 mm) was formed by extrusion molding black-colored low-density polyethylene so as to cover the outer surface of the composite pipe covered with the reinforcing tape 17. In this way, a composite resin pipe for hydrogen transport 10 (inner diameter: 53 mm, outer diameter: 58 mm) was produced.

[0029] (2) Hydrogen permeation test The hydrogen permeation rate of the composite resin pipe for hydrogen transportation produced in each example was measured in the following manner.

[0030] (2a) Preparation of test specimen A composite resin pipe for hydrogen transport was cut to a length of 1 m, and the end was processed for piping connection, and a jig was attached to prepare a test specimen as shown in Figure 4.

[0031] (2b) Construction of the test equipment A test apparatus 30 with a piping flow as shown in FIG. 5 was constructed. The test apparatus 30 (piping flow) shown in FIG. 5 is piped downstream from a hydrogen cylinder 33, passing through a pressure reducing valve 34, a filter 36, a manual valve 38, a pressure sensor 40, and a manual valve 42, and then connected to the test specimen 11. A manual valve 44 is connected to the piping branching between the manual valve 38 and the pressure sensor 40, and is configured to be ventable. A hydrogen permeation rate measuring unit 46 is provided in the longitudinal center of the test specimen 11. The hydrogen permeation rate measuring unit 46 is configured as an enclosed space capable of capturing hydrogen gas leaking from the outer peripheral surface of the longitudinal center by covering the outer periphery of the longitudinal center of the test specimen 11 with a resin film bag. In other words, the hydrogen permeation rate measuring unit 46 is configured to be suitable for measuring the hydrogen concentration in an enclosed space covered with a resin film bag. The hydrogen permeation rate measuring section 46 is piped to be connected to a gas chromatograph 52 (Agilent Micro GC3000A (minimum resolution: 1 ppm)) via manual valves 48 and 50. Ar gas is piped to be supplied to each of the gas chromatograph 52 and a mass flow controller 56. The mass flow controller 56 is piped to be connected to the hydrogen permeation rate measuring section 46 via manual valve 58, check valve 60, and manual valve 62, so that Ar gas can be supplied into the hydrogen permeation rate measuring section 46 at a flow rate controlled by the mass flow controller 56. A thermometer 64 is attached to the surface of the test piece 11, and a thermometer 66 is also installed in the room in which the test piece 11 is placed to measure the ambient temperature within the room.

[0032] (2c) Hydrogen permeation test and data collection In the test apparatus 30 constructed in this manner, hydrogen gas was supplied into the test piece 11 (i.e., the composite pipe 10), and the amount of hydrogen gas leaking from the outer surface of the test piece 11 (i.e., the hydrogen permeation amount) in the hydrogen permeation amount measuring section 46 was measured by a gas chromatograph 52. The test conditions and test fluids used in this measurement were as follows: <Test conditions> Test temperature: Room temperature Test pressure (hydrogen gas pressure): 1 MPaG Measurement time: 100 hours or more Gas chromatograph purge gas volume: 50 ml / min <Test fluid> Gas for checking airtightness: Helium gas (purity: 99.99%) Test gas: Hydrogen gas (purity: 99.9%) Gas chromatograph purge gas: Argon gas (purity: 99.999%) Gas chromatograph carrier gas: Argon gas (purity: 99.999%)

[0033] In the above measurements, the following four types of data were collected using a general-purpose data logger (Keyence Corporation, NR-600, sampling interval: 100 ms). Pressure: The output of a pressure sensor 40 (KJ-16 intrinsically safe explosion-proof pressure transmitter, 1-5VDC, manufactured by Nagano Keiki Co., Ltd.) was recorded as pressure P1. · Test specimen surface temperature: Thermometer 64 (T-type thermocouple) was inserted into the explosion-proof cover, and the surface temperature Ts1 of test specimen 11 was measured and recorded. · Environmental temperature: Thermometer 66 (T-type thermocouple) was inserted into the explosion-proof cover, and the environmental temperature Ta1 was measured and recorded. Hydrogen content: Data on the amount of hydrogen permeated was collected using a gas chromatograph.

[0034] (2d) Result The test results obtained were as follows:

[0035] <Test waveform and logger data> The measured values ​​of the logger data collected during the test are shown in Table 1. Figure 6 shows the test waveform of the hydrogen permeation test obtained for the specimen of Example 1, and Figure 7 shows the test waveform of the hydrogen permeation test obtained for the specimen of Example 2. [Table 1]

[0036] <Hydrogen permeation measurement results> The results of measuring the hydrogen permeation amount are shown in Table 2. In addition, Fig. 8 shows the change over time in the hydrogen permeation amount per unit length measured for the test specimens of Examples 1 and 2.

[0037] [Table 2]

[0038] (2e) Discussion As shown in Table 2, the hydrogen permeation rate (average value) of the specimen in Example 1 was 0.1741 ml / (min m), and the hydrogen permeation rate of the specimen in Example 2 was 0.00777 ml / (min m). Using these values ​​and the dimensions of the specimen, the following formula was used: Hydrogen permeability coefficient = (hydrogen permeation amount (volume)) x (tube thickness) / [(pressure difference) x (permeation area) x (time)] When converted into a gas permeability constant using the formula, the values ​​shown in Table 3 were obtained. [Table 3]

[0039] The hydrogen permeability coefficients of the specimens of Examples 1 and 2 shown in Table 3 are the same as the permeability coefficient (PC) of polyethylene pipes described in Non-Patent Document 2, which is 126.8 (ml·mm) / (m 2 1.5×10 -13 (cm 3 cm) / (cm 2 ·s·Pa), indicating excellent resistance to hydrogen permeation.

[0040] Furthermore, a comparison of Example 1 (aluminum layer thickness: 0.0635 mm) and Example 2 (aluminum layer thickness: 0.127 mm) reveals that the specimen of Example 2, which has a thicker aluminum layer, has a lower hydrogen permeability coefficient than the specimen of Example 1. This suggests that a thicker first reinforcing layer (aluminum layer) has a greater effect in suppressing hydrogen permeation. [Explanation of symbols]

[0041] 10. Composite resin pipe for transporting hydrogen 12 Inner tube 14 First reinforcement layer 16 Second reinforcement layer 17 Reinforcement tape 18 Anti-corrosion layer 20 Nonwoven fabric

Claims

1. A composite resin pipe for transporting hydrogen, A resin inner tube; a first reinforcing layer made of aluminum covering an outer peripheral surface of the inner pipe; A second reinforcing layer made of a unidirectional fiber-reinforced thermoplastic composite material covering the outer surface of the first reinforcing layer; a corrosion protection layer covering an outer surface of the second reinforcing layer and including at least one resin selected from the group consisting of vinyl chloride resin, epoxy resin, polyethylene resin, urethane resin, and fluorine-based resin; A composite resin pipe for transporting hydrogen, comprising:

2. 2. The composite resin pipe for transporting hydrogen according to claim 1, wherein the resin constituting the inner pipe includes polyethylene or polyamide.

3. 2. The composite resin pipe for transporting hydrogen according to claim 1, wherein the resin constituting the inner pipe is high-density polyethylene.

4. 4. The resin composite pipe for transporting hydrogen according to claim 1, wherein the unidirectional fiber-reinforced thermoplastic composite material comprises glass fibers oriented in one direction and a polyethylene terephthalate (PET) resin impregnated into the glass fibers.

5. 5. The composite resin pipe for transporting hydrogen according to claim 4, wherein the polyethylene terephthalate (PET) resin is an amorphous polyethylene terephthalate (A-PET) resin.

6. The composite resin pipe for transporting hydrogen according to any one of claims 1 to 3, wherein the first reinforcing layer and the second reinforcing layer are provided by a reinforcing tape including the first reinforcing layer and the second reinforcing layer.

7. The composite resin pipe for transporting hydrogen according to any one of claims 1 to 3, wherein the anticorrosion layer contains a low-density polyethylene resin or a vinyl chloride resin.

8. 4. The composite resin pipe for transporting hydrogen according to claim 1, wherein the thickness of the inner pipe is 3.0 mm or more and 13.0 mm or less.

9. 4. The composite resin pipe for transporting hydrogen according to claim 1, wherein the first reinforcing layer has a thickness of 0.01 mm or more and 0.5 mm or less.

10. 4. The composite resin pipe for transporting hydrogen according to claim 1, wherein the second reinforcing layer has a thickness of 0.1 mm or more and 1.0 mm or less.

11. 4. The composite resin pipe for transporting hydrogen according to claim 1, wherein the thickness of the anticorrosion layer is 1.0 mm or more and 3.0 mm or less.

12. The inner diameter of the resin composite pipe for hydrogen transport is 35.0 mm or more and 120.0 mm or less, and the outer diameter of the resin composite pipe for hydrogen transport is 40.0 mm or more and 130.0 mm or less. A resin composite pipe for hydrogen transport according to any one of claims 1 to 3.

13. 4. The composite resin pipe for transporting hydrogen according to claim 1, further comprising a nonwoven fabric between the inner pipe and the first reinforcing layer, the nonwoven fabric covering an outer peripheral surface of the inner pipe.

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