Connecting mechanism of large-diameter high-pressure hydrogen conveying composite pipe

Abstract

The utility model discloses a connecting mechanism of a large-caliber high-pressure hydrogen conveying composite pipe, which comprises a first metal buckling joint and a second metal buckling joint, and the opposite ends of the first metal buckling joint and the second metal buckling joint are fixedly connected through a thread buckle to form a connecting joint; tooth-shaped channels extending in the axial direction are formed in the opposite ends of the first metal buckling and pressing connector and the second metal buckling and pressing connector; the tooth-shaped channel is matched with a structural layer of a composite pipe to be connected; a lining pipe joint is fixedly arranged on the inner side of the connecting joint; the outer side of the connecting joint is fixedly sleeved with an air guide interlayer; the outer side of the air guide interlayer is fixedly sleeved with a hot melting sleeve. According to the utility model, the large-diameter high-pressure hydrogen conveying composite pipes with the inner diameter of more than 150mm can be connected, so that the large-diameter composite pipes can realize long-distance high-pressure hydrogen conveying, and meanwhile, hydrogen brittleness threats are avoided. The utility model further discloses a connecting method of the large-diameter high-pressure hydrogen conveying composite pipe.

Description

Technical Field

[0001] The utility model relates to high-pressure hydrogen transmission equipment, in particular to a connecting mechanism of a large-diameter high-pressure hydrogen transmission composite pipe. Background Art

[0002] As the ultimate form of energy, hydrogen is highly anticipated by mankind. In recent years, with the development of solar power and wind power, in order to stabilize the instability of green electricity and develop the electrolysis of water to produce hydrogen, hydrogen energy has been given the function of energy storage medium. However, the ultimate goal of hydrogen energy is to be consumed, and the high storage and transportation costs have become the main obstacle to the popularization and application of hydrogen energy. Hydrogen is large in volume and must be compressed into a smaller volume for storage and transportation in order to be economical.

[0003] High-pressure pipeline transportation is the most ideal way to transport hydrogen from the production area to the consumption area over long distances. However, high-pressure pipeline transportation of hydrogen is a global problem. This is because hydrogen molecules are the smallest, and high-pressure transportation using steel pipes will cause hydrogen embrittlement, resulting in rupture and leakage. Therefore, the pressure of ordinary steel pipes for hydrogen transportation cannot exceed 2.5MPa, which greatly limits the advantages of pipeline transportation.

[0004] To this end, the industry has tried to use fiber-reinforced composite pipes made of polymer materials to transport hydrogen. However, although plastic pipes can avoid hydrogen embrittlement, they have various problems caused by hydrogen penetration under high pressure. In particular, solving the connection problem between pipes is a test of both technology and cost. For small-diameter composite continuous pipes with an inner diameter of about 100mm, because their continuous length is long enough and there are few joints, the unit cost is acceptable after the cost is amortized; however, the unit hydrogen transport cost advantage of small-diameter pipelines is not large, and the maximum inner diameter of the coiled continuous pipe can only be 150mm. Large-diameter composite pipes exceeding this size cannot be coiled. Like steel pipes, they need to be cut into standard lengths first, and then connected one by one at the construction site. The technical reliability and cost acceptability are both negative. Therefore, the current high-pressure hydrogen transport of composite pipes only shows the advantages of small-diameter composite continuous pipes in special occasions such as offshore wind power hydrogen production and transport back to land. There are few reports on the use of large-diameter composite pipes for high-pressure hydrogen transport.

[0005] The technical barriers to using large-diameter composite pipes for high-pressure hydrogen transportation come from two aspects. First, the problem of hydrogen permeation in the pipe body; when polymer materials are used as containers for high-pressure hydrogen, gas permeation is inevitable. The accumulation of permeated hydrogen in the pipe trench and the accumulation of permeation pressure in the middle of the pipe wall will bring safety problems during high-pressure transportation. Second, large-diameter composite pipes can only be short pipes that meet transportation specifications rather than continuous pipes, so they need to be connected one by one. The existing composite pipe welding method cannot meet the requirements of high-pressure hydrogen transportation. Therefore, it is still necessary to use metal parts to clamp the pipe body and connection to improve the pressure resistance level of the composite pipe connection; and metal clamping parts, like steel pipes for hydrogen transportation, are subject to the threat of hydrogen embrittlement; if special stainless steel resistant to hydrogen embrittlement is used, the cost is high; in addition, whether the seal at the clamping of the composite pipe body is reliable is also questionable.

[0006] Chinese utility model patent document CN115013729B discloses a medium- and high-pressure gas delivery system and method using a double-layer airway composite pipe, which can be used for high-pressure hydrogen delivery above 10 MPa. The first problem is solved by the method of drainage, but the second problem of hydrogen delivery through large-diameter composite pipes is not solved. Utility Model Content

[0007] The technical problem to be solved by the utility model is to provide a connection mechanism for large-diameter high-pressure hydrogen transport composite pipes, which can realize the connection between large-diameter high-pressure hydrogen transport composite pipes with an inner diameter of more than 150mm, so that the large-diameter composite pipes can realize long-distance high-pressure hydrogen transport, while avoiding the threat of hydrogen embrittlement of metal crimping joints.

[0008] In order to solve the above technical problems, the technical solution of the connection mechanism of the large-diameter high-pressure hydrogen transmission composite pipe of the utility model is:

[0009] It includes a first metal crimping joint 1 and a second metal crimping joint 2, and the opposite ends of the first metal crimping joint 1 and the second metal crimping joint 2 are fixedly connected by a threaded buckle 1-1 to form a connecting joint; the opposite ends of the first metal crimping joint 1 and the second metal crimping joint 2 are formed with a toothed channel 11 extending in the axial direction; the toothed channel 11 matches the thickness of the structural layer of the composite pipe to be connected, and the fixed connection between the composite pipe and the metal crimping joint 1 is achieved by the matching connection between the structural layer 94 of the composite pipe and the toothed channel of the metal crimping joint 1; an inner lining pipe section 4 is fixedly arranged on the inner side of the connecting joint; an outer fixing sleeve of the connecting joint is provided with an air-conducting interlayer 3; the length of the air-conducting interlayer 3 matches the length of the outer ring of the connecting joint; an outer fixing sleeve of the air-conducting interlayer 3 is provided with a hot-melt sleeve 5; the length of the hot-melt sleeve 5 is greater than the length of the air-conducting interlayer 3.

[0010] In another embodiment, the first metal crimping joint 1 is a male crimping joint; the second metal crimping joint 2 is a female crimping joint.

[0011] In another embodiment, the inner diameter of the composite tube is greater than 150 mm.

[0012] In another embodiment, the toothed channel 11 is composed of inner ring teeth 11 - 1 and outer ring teeth 11 - 2 that are arranged opposite to each other.

[0013] In another embodiment, the outer diameter of the inner ring teeth 11 - 1 is slightly larger than the inner diameter of the structural layer 94 of the composite tube; the outer diameter of the outer ring teeth 11 - 2 is slightly larger than the outer diameter of the structural layer 94 of the composite tube.

[0014] In another embodiment, the inner liner pipe section 4 includes a non-metallic liner pipe 41 and a metal support pipe 42 fixedly connected as one; the length of the metal support pipe 42 matches the inner ring length of the connecting joint; the length of the non-metallic liner pipe 41 is greater than that of the metal support pipe 42.

[0015] In another embodiment, slopes 41 - 1 are formed at both ends of the non-metallic liner 41 ; the slopes 41 - 1 match the slopes 95 - 1 of the connecting ends of the inner liner layer 95 of the composite pipe to be connected.

[0016] In another embodiment, the length of the slope 41 - 1 and the slope 95 - 1 is more than twice the wall thickness of the non-metallic liner 41 .

[0017] In another embodiment, the non-metallic liner tube 41 is made of polymer material; the metal support tube 42 is made of corrosion-resistant stainless steel material.

[0018] In another embodiment, the air-conducting interlayer 3 includes an air-conducting interlayer outer protective layer 31, an air-conducting structural layer 32 and a corrugated air-conducting layer 33 which are arranged in sequence from the outside to the inside; the inner hole of the corrugated air-conducting layer 33 has regularly or irregularly distributed convex portions 33-1 and concave portions 33-2; the convex portion 33-1 of the corrugated air-conducting layer 33 cooperates with the connecting joint; a gap H is formed between the concave portion 33-2 of the corrugated air-conducting layer 33 and the connecting joint.

[0019] The technical effects that can be achieved by the utility model are:

[0020] The utility model can realize the fixed connection between two sections of composite pipes and can withstand the high pressure of the medium pressure in the pipe being more than 10MPa.

[0021] The utility model provides a flow air channel in the connecting mechanism so that the infiltrated hydrogen can flow and be discharged out of the pipe body.

[0022] The utility model connects the main structure of the composite pipe, i.e., the structural layer, through the toothed channel of the metal crimping joint, and realizes a fixed connection between the metal crimping joint and the structural layer of the composite pipe through a crimping device, thereby ensuring the firmness of the connection between the crimping joint and the composite pipe.

[0023] The utility model realizes the connection between two sections of composite pipes through a metal crimping joint, which can facilitate the rapid and stable connection between the composite pipes; and, the utility model is provided with an inner liner pipe section on the inner ring of the metal crimping joint, and a non-metallic sealing layer is also provided outside the air guide interlayer of the outer ring of the metal crimping joint, so that all metal components are hidden in the pipe wall, and the inside does not contact the high-pressure fluid, and the outside does not contact the soil and other substances in the trench.

[0024] The utility model does not need to use fire during the installation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] It should be understood by those skilled in the art that the following description is only intended to schematically illustrate the principles of the present invention, which can be applied in a variety of ways to achieve many different alternative embodiments. These descriptions are only used to illustrate the general principles of the teachings of the present invention and are not intended to limit the utility model concepts disclosed herein.

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the general description above and the detailed description of the drawings below, are used to explain the principles of the present invention.

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] Figure 1 It is a schematic diagram of the connection mechanism of the large-diameter high-pressure hydrogen transmission composite pipe of the utility model;

[0029] Figure 2 yes Figure 1 AA section diagram in;

[0030] Figure 3 yes Figure 1 BB cross-section diagram in FIG.

[0031] Figure 4 It is a schematic diagram of a first metal crimping joint of the utility model;

[0032] Figure 5 is a schematic diagram of a second metal crimping joint of the utility model;

[0033] Figure 6 It is a schematic diagram of the inner liner pipe section of the utility model;

[0034] Figure 7It is a schematic diagram of the air-conducting interlayer of the utility model;

[0035] Figure 8 This is a schematic diagram of stripping the connection end of the composite pipe;

[0036] Fig. 9 It is a schematic diagram of crimping the metal crimping joint to the connecting end of the composite pipe; E1 is the installation direction, and E2 is the crimping direction;

[0037] Fig.10 It is a schematic diagram of pre-connecting the liner pipe section, the gas conducting interlayer and the hot melt sleeve with one section of the composite pipe;

[0038] Fig.11 is a schematic diagram of tightening and fixing the first metal crimping joint and the second metal crimping joint;

[0039] Fig.12 It is a schematic diagram of fixedly connecting the hot melt sleeve, the air guide interlayer and the connecting ends of the two sections of composite pipes.

[0040] Description of reference numerals in the figures:

[0041] 1 is the first metal crimping joint, 2 is the second metal crimping joint,

[0042] 11 is a toothed channel, 12 is a snap-on male thread,

[0043] 11-1 is the inner ring teeth of the toothed channel, 11-2 is the outer ring teeth of the toothed channel,

[0044] 21 is a snap-on female thread, 22 is a toothed channel,

[0045] 3 is the air-conducting interlayer, 4 is the inner lining pipe section,

[0046] 41 is a non-metallic liner pipe of the inner liner pipe section, 42 is a metal support pipe of the inner liner pipe section,

[0047] 31 is the outer protective layer of the air-conducting interlayer, 32 is the air-conducting structural layer,

[0048] 33 is a corrugated air guide layer,

[0049] 5 is a hot melt sleeve,

[0050] 91 is the outer protective layer of the composite pipe, 92 is the outer structural layer of the composite pipe,

[0051] 93 is the low-pressure gas-conducting layer of the composite pipe, 94 is the structural layer of the composite pipe,

[0052] 95 is the inner lining layer of the composite pipe. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution of the embodiment of the utility model will be clearly and completely described in conjunction with the drawings of the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the described embodiment of the utility model, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the utility model. Unless otherwise defined, the technical terms or scientific terms used herein should be the usual meanings understood by people with ordinary skills in the field to which the utility model belongs. The "first", "second" and similar words used in this article do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe of the utility model can fix and connect two sections of multi-layer composite pipes with an inner diameter of more than 150 mm together; the composite pipe includes an outer protective layer 91, an outer structural layer 92, a low-pressure gas guide layer 93, a structural layer 94 and an inner lining layer 95 arranged in sequence from the outside to the inside, such as Figure 2 As shown;

[0055] Specifically, the composite pipe may be a composite pipe disclosed in Chinese utility model patent document CN115013729B;

[0056] like Figure 1 , Figure 3 As shown, the connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe of the utility model comprises a first metal crimping joint 1 and a second metal crimping joint 2, the opposite end of the first metal crimping joint 1 matches the connection end of the first composite pipe, and the opposite end of the second metal crimping joint 2 matches the connection end of the second composite pipe;

[0057] The first metal crimping joint 1 and the second metal crimping joint 2 are respectively provided with matching snap-on threads at their opposite ends, and the first metal crimping joint 1 and the second metal crimping joint 2 are fixedly connected by the threaded snap-on 1-1 to form a connecting joint;

[0058] like Figure 4As shown, the first metal crimping joint 1 is a male crimping joint; a snap-on male thread 12 is formed at one end (i.e., the opposite end) of the first metal crimping joint 1; a toothed channel 11 extending in the axial direction is formed at the other end (i.e., the opposite end) of the first metal crimping joint 1; the toothed channel 11 is composed of inner ring teeth 11-1 and outer ring teeth 11-2 arranged oppositely; the toothed channel 11 matches the thickness of the structural layer of the first composite pipe, so that the structural layer 94 of the first composite pipe can extend into the toothed channel 11 of the first metal crimping joint 1, thereby forming a fixed connection between the composite pipe and the first metal crimping joint 1;

[0059] Furthermore, the outer diameter of the inner ring gear 11-1 is slightly larger than the inner diameter of the structural layer 94 of the composite tube, so that the inner ring gear 11-1 and the structural layer 94 of the composite tube are connected in an interference fit manner;

[0060] The outer diameter of the outer ring teeth 11 - 2 is slightly larger than the outer diameter of the structural layer 94 of the composite pipe, so that the outer ring teeth 11 - 2 and the structural layer 94 of the composite pipe are connected in a clearance fit manner;

[0061] like Figure 5 As shown, the second metal crimping joint 2 is a female crimping joint; a snap-on female thread 21 is formed at one end (i.e., the opposite end) of the second metal crimping joint 2; the snap-on female thread 21 of the second metal crimping joint 2 matches the snap-on male thread 12 of the first metal crimping joint 1;

[0062] The other end (i.e., the opposite end) of the second metal crimping joint 2 is formed with a toothed channel 22 extending in the axial direction, and the toothed channel 22 matches the thickness of the structural layer of the second composite pipe, so that the structural layer 94 of the second composite pipe can extend into the toothed channel 22 of the second metal crimping joint 2, thereby forming a fixed connection between the composite pipe and the second metal crimping joint 2;

[0063] The inner side of the connection joint is provided with a liner pipe section 4; the liner pipe section 4 spans the connection joint; specifically, as Figure 6 As shown, the liner pipe section 4 is an integral prefabricated part symmetrical at both ends, including a non-metallic liner pipe 41 and a metal support pipe 42 fixedly connected as one body by injection molding; the length of the non-metallic liner pipe 41 is greater than that of the metal support pipe 42; the length of the metal support pipe 42 matches the inner circle length of the connecting joint composed of the first metal crimping joint 1 and the second metal crimping joint 2, and the non-metallic liner pipe 41 can wrap the metal support pipe 42 and the metal joint from the inside to avoid metal exposure;

[0064] Preferably, the material of the non-metallic liner 41 may be a polymer material;

[0065] The material of the metal support tube 42 can be corrosion-resistant stainless steel;

[0066] The utility model provides the inner liner pipe segment 4 with a metal support pipe 42 as a skeleton, so that the inner liner pipe segment 4 has sufficient strength; at the same time, a non-metallic liner pipe 41 is provided in direct contact with the medium, so that the inner liner pipe segment 4 has sufficient corrosion resistance and anti-scaling ability.

[0067] The metal support pipe 42 and the non-metal liner pipe 41 of the utility model are welded together by injection molding, which can greatly eliminate the gap between the two layers of material of the inner liner pipe section 4.

[0068] Furthermore, slopes 41-1 are formed at both ends of the non-metallic liner 41; the slopes 41-1 match the slopes 95-1 of the inner liner 95 of the composite pipe to be connected; the slopes 95-1 of the inner liner 95 can be formed by machining;

[0069] The length of the slope 41-1 and the slope 95-1 can be more than twice the wall thickness of the non-metallic liner 41; by increasing the length of the slope 41-1 and the slope 95-1, the connection strength between the two welded pipes (ie, the non-metallic liner 41 and the inner lining layer 95) can be increased.

[0070] The outer side of the connection joint is provided with an air-conducting interlayer 3; the air-conducting interlayer 3 is an extension of the low-pressure air-conducting layer 93 of the multilayer composite tube, and its length covers the connection joint; specifically, the length of the air-conducting interlayer 3 matches the outer ring length of the connection joint composed of the first metal crimping joint 1 and the second metal crimping joint 2, so that the metal joint can be wrapped inside from the outside; Figure 7 As shown, the air guiding interlayer 3 comprises an air guiding interlayer outer protective layer 31, an air guiding structure layer 32 and a corrugated air guiding layer 33 arranged in sequence from the outside to the inside; the inner hole of the corrugated air guiding layer 33 has regularly or irregularly distributed convex parts 33-1 and concave parts 33-2;

[0071] The convex portion 33 - 1 of the corrugated air guide layer 33 cooperates with the connecting joint, so that a fixed connection is formed between the air guide interlayer 3 and the connecting joint;

[0072] A gap H is formed between the concave portion 33-2 of the corrugated gas-conducting layer 33 and the connecting joint, so that a plurality of gas-conducting channels are formed between the gas-conducting interlayer 3 and the connecting joint, which are used to connect the low-pressure gas-conducting layers of the two sections of the composite pipe;

[0073] The corrugated air guide layer 33 can be formed by injection molding;

[0074] Since the function of the low-pressure gas-conducting layer of the composite pipe is to transmit the gas that permeates from the inside of the pipeline through the gaps between the molecules of the composite material; during the working process, the first composite pipe forms low-pressure gas in its low-pressure gas-conducting layer, and the low-pressure gas is transported to the low-pressure gas-conducting layer of the second composite pipe through the multiple gas-conducting channels of the connecting structure of the composite pipe of the utility model, so that the gas-conducting layers of the two pipes are connected, so that the low-pressure gas can be discharged to the outside along the high-pressure hydrogen transmission pipeline composed of multiple composite pipes; the utility model sets a circulation airway to allow the permeated hydrogen to circulate and be discharged out of the pipe body.

[0075] The air-conducting structural layer 32 can increase the structural strength of the air-conducting interlayer 3 ; since the gas in the air-conducting layer also has a certain pressure, the air-conducting structural layer 32 can prevent the air-conducting interlayer 3 from being deformed and damaged by pressure.

[0076] The outer protective layer 31 of the air-conducting interlayer can play a protective role, and as a filling structure, provide support for the subsequent hot melt sleeve operation and good pressure conduction effect;

[0077] The outer side of the air-conducting interlayer 3 is covered with a hot-melt sleeve 5 ; the length of the hot-melt sleeve 5 is greater than that of the air-conducting interlayer 3 , so that the connection between the air-conducting interlayer 3 and the two sections of the composite pipe can be wrapped inside.

[0078] The utility model discloses a method for connecting a large-diameter high-pressure hydrogen transmission composite pipe, comprising the following steps:

[0079] The first step is to strip the connecting ends of the two sections of the composite pipe to be connected respectively;

[0080] like Figure 8 As shown, the connecting ends of the two sections of composite pipes to be connected are processed so that the structural layer 94 of the composite pipe is exposed;

[0081] Preferably, in order to facilitate the tube stripping operation, part of the low-pressure gas-conducting layer 93 and part of the lining layer 95 adjacent to the structural layer 94 may be retained;

[0082] The second step is to connect the metal crimping joint and the composite pipe;

[0083] like Fig. 9 As shown, a crimping device is used to crimp the first metal crimping joint 1 and the second metal crimping joint 2 to the connecting ends of the two sections of composite pipes respectively;

[0084] The exposed structural layer 94 (and part of the low-pressure air guide layer 93 and / or part of the lining layer 95) is extended into the toothed channel 11 of the first metal crimping joint 1 or the toothed channel 22 of the second metal crimping joint 2; the outer ring teeth 11-2 of the toothed channel are crimped and compressed by a crimping device; the outer diameter of the outer ring teeth 11-2 is reduced by a hydraulic device or an electric device; when the outer ring teeth 11-2 are plastically deformed, the tooth shape of the outer ring teeth 11-2 will be concave toward the center of the pipeline, thereby compressing the structural layer 94 (and part of the low-pressure air guide layer 93 and / or part of the lining layer 95) of the composite pipe. The compressive force generated by the plastic deformation of the outer ring teeth 11-2 is transmitted inward to the inner ring teeth 11-1 through the structural layer 94 of the composite pipe, but the force is not large enough to cause the inner ring teeth 11-1 to plastically deform. As a result, under the action of the contraction force of the plastic deformation of the outer ring teeth 11-2, the outer ring teeth 11-2 and the inner ring teeth 11-1 can form an effect of clamping the pipe wall (i.e., the structural layer 94 of the composite pipe, or the structural layer 94 and part of the low-pressure air-conducting layer 93 and / or part of the inner lining layer 95).

[0085] Since the pipe body of the composite pipe is a composite material, the pipe body has strong plasticity and is relatively soft, and will undergo obvious elastic deformation under the action of external force. The utility model utilizes this feature, and in the process of connecting the composite pipe with the metal crimping joint, the structural layer 94 of the composite pipe and part of the low-pressure air-conducting layer 93 and / or part of the inner lining layer 95 undergo plastic deformation under stress, so that the structural layer 94 of the composite pipe and part of the low-pressure air-conducting layer 93 and / or part of the inner lining layer 95 can fill the toothed channel of the metal crimping joint, thereby further enhancing the connection force between the metal crimping joint and the pipe to be connected, and can play a strong sealing role.

[0086] The third step is to pre-connect the liner pipe section 4, the air guide interlayer 3 and the hot melt sleeve 5 with one section of the composite pipe;

[0087] like Fig.10 As shown, the inner liner pipe section 4 is arranged in the inner hole of the composite pipe, the gas-conducting interlayer 3 is arranged in the outer ring of the composite pipe; the hot-melt sleeve 5 is hollowly sleeved on the composite pipe;

[0088] The fourth step is to connect the metal crimping joints, and screw and fasten the first metal crimping joint 1 and the second metal crimping joint 2 which are respectively connected to the two sections of the composite pipe. Fig.11 As shown;

[0089] The utility model realizes the connection between the pipes through the spiral buckle, which is convenient for construction.

[0090] Step 5: Connect the hot melt sleeve 5 and heat it;

[0091] First, the hot melt sleeve 5 is moved to the air guide interlayer 3, so that the hot melt sleeve 5 wraps the connecting portion between the air guide interlayer 3 and the two sections of the composite pipe; then the hot melt sleeve 5 is heated until the hot melt sleeve 5, the outer protective layer 31 of the air guide interlayer, and the outer protective layer 91 of the composite pipe are integrated, so that the hot melt sleeve 5 is fixedly connected to the air guide interlayer 3 and the connecting end of the two sections of the composite pipe. Fig.12 As shown;

[0092] Step 6: The non-metallic liner 41 of the inner liner pipe section 4 is fixedly connected to the inner liner layer 95 of the composite pipe by laser or ultrasonic welding;

[0093] The inner liner pipe segment 4 is fixedly connected to the inner liner layers 95 of the two sections of the composite pipe by laser welding; since the laser welding surface between the non-metallic liner pipe 41 of the inner liner pipe segment 4 and the inner liner layer 95 of the composite pipe is an inclined surface, the inclined surface can improve the welding quality between the polymer materials (i.e., the non-metallic liner pipe 41 and the inner liner layer 95), and improve the connection firmness between the non-metallic liner pipe 41 and the inner liner layer 95, thereby achieving a firm connection between the inner liner pipe segment 4 and the inner liner layer 95 of the composite pipe.

[0094] The utility model uses laser welding to achieve plastic welding of the non-metallic liner pipe 41 and the inner liner layer 95 between the inner liner pipe section 4 and the composite pipe, which can ensure the sealing performance of the inner side of the joint.

[0095] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A connection mechanism for a large-diameter high-pressure hydrogen transport composite pipe, characterized in that: It comprises a first metal crimping joint and a second metal crimping joint, wherein the first metal crimping joint and the second metal crimping joint are fixedly connected at opposite ends by threaded buckles to form a connecting joint; The first metal crimping joint and the second metal crimping joint are formed with tooth-shaped channels extending in the axial direction at the opposite ends thereof; the tooth-shaped channels match the structural layer of the composite pipe to be connected, and the fixed connection between the composite pipe and the metal crimping joint is achieved through the matching connection between the structural layer of the composite pipe and the tooth-shaped channels of the metal crimping joint; An inner lining pipe section is fixedly arranged on the inner side of the connecting joint; The outer fixed sleeve of the connection joint is provided with an air-conducting interlayer; the length of the air-conducting interlayer matches the length of the outer ring of the connection joint; The outer fixing sleeve of the air-conducting interlayer is provided with a hot-melt sleeve; the length of the hot-melt sleeve is greater than the length of the air-conducting interlayer.

2. The connecting mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 1 is characterized in that: The toothed channel is composed of inner ring teeth and outer ring teeth which are arranged opposite to each other.

3. The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 2 is characterized in that: The outer diameter of the inner ring teeth is slightly larger than the inner diameter of the structural layer of the composite pipe; the outer diameter of the outer ring teeth is slightly larger than the outer diameter of the structural layer of the composite pipe.

4. The connecting mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 1 is characterized in that: The inner liner pipe section comprises a non-metallic liner pipe and a metal support pipe which are fixedly connected as one; the length of the metal support pipe matches the inner ring length of the connecting joint; and the length of the non-metallic liner pipe is greater than that of the metal support pipe.

5. The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 4 is characterized in that: Both ends of the non-metallic liner pipe form slopes respectively; the slopes match the slopes of the connecting ends of the inner liner layer of the composite pipe to be connected.

6. The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 5 is characterized in that: The ramp and the length of the ramp are more than twice the wall thickness of the non-metallic liner.

7. The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 4 is characterized in that: The material of the non-metallic liner is a polymer material; the material of the metal support tube is a corrosion-resistant stainless steel material.

8. The connecting mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 1 is characterized in that: The air-conducting interlayer comprises an air-conducting interlayer outer protective layer, an air-conducting structural layer and a corrugated air-conducting layer which are arranged in sequence from the outside to the inside; the inner hole of the corrugated air-conducting layer has convexities and concave portions which are regularly or irregularly distributed; the convexity of the corrugated air-conducting layer cooperates with the connecting joint; and a gap is formed between the concave portion of the corrugated air-conducting layer and the connecting joint.

9. The connecting mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 1, characterized in that: The first metal crimping joint is a male crimping joint; the second metal crimping joint is a female crimping joint.

10. The connection mechanism of the large-diameter high-pressure hydrogen transport composite pipe according to claim 1, characterized in that: The inner diameter of the composite pipe is greater than 150 mm.

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