Non-adhesive flexible composite pipe

Abstract

The invention discloses a non-adhesive flexible composite pipe, relates to the technical field of offshore oil and gas transmission and offshore hydrogen energy transmission, and solves the problems of complex process, short service life of materials and large overall weight of a pipeline in the existing structure. Comprising a framework layer, an inner pressure sealing layer, a pressure-resistant armor layer, a first auxiliary layer, a tensile armor layer and an outer coating layer which are sequentially arranged from inside to outside, all the layers are in non-bonding connection, the inner pressure sealing layer and the outer coating layer are PA11 material layers, the pressure-resistant armor layer bears the pressure difference between the inside and the outside of the pipeline, the first auxiliary layer buffers and isolates a conveying medium in the pipeline, and the tensile armor layer is a PA11 material layer. And the tensile armor layer bears axial tension. On the premise of ensuring the medium conveying safety, the wear resistance is improved, the problem that the service life of each coating layer of the flexible pipe is short is solved, the design life of the non-adhesive flexible composite pipeline is effectively prolonged, the cost is reduced by reducing the number of the tensile armor layers, and the non-adhesive flexible composite pipeline has the advantages of being reasonable in structure, light in weight, high in production efficiency, low in cost and long in service life.

Description

Technical Field

[0001] This invention relates to the field of marine oil and gas transportation and marine hydrogen transportation technology, and particularly to a non-bonded flexible composite pipe. Background Technology

[0002] Hydrogen energy, as a clean energy carrier with great potential, can ensure the large-scale consumption of renewable energy. Hydrogen transportation in the midstream of the hydrogen energy industry chain is a key link connecting upstream hydrogen production and downstream hydrogen utilization, especially in the field of offshore wind power hydrogen production. In order to adapt to its characteristics such as wave fatigue, non-bonded flexible composite pipelines are widely used in submarine transportation systems due to their good flexibility, strong corrosion resistance and low installation cost (compared to rigid steel pipes). They have also become the best choice for hydrogen transportation pipelines for future offshore wind power coupled hydrogen production.

[0003] Existing high-temperature resistant non-bonded flexible composite pipelines typically employ an extruded sacrificial layer structure between the skeleton layer and the internal pressure sealing layer, usually using polyester tape. While this structure can alleviate the problem of extrusion stress concentration, it suffers from drawbacks such as complex manufacturing processes, short material lifespan, and relatively high overall pipeline weight, and is not conducive to reducing manufacturing costs or improving laying efficiency. Therefore, it is necessary to provide a non-bonded flexible composite pipeline with a simpler structure, lighter weight, and still meeting the requirements for transporting high-temperature media. Summary of the Invention

[0004] The purpose of this invention is to provide a non-bonded flexible composite pipe for transporting media such as hydrogen produced by offshore wind power (and also for transporting oil and gas). Both the inner pressure sealing layer and the outer coating layer are made of PA11 (Polyamide 11, poly-ω-aminoundecylamide). While ensuring the safety of media transportation, it improves wear resistance, overcomes the problem of short service life of each coating layer of flexible pipe, effectively improves the design life of non-bonded flexible composite pipelines, and reduces costs by reducing the number of tensile armor layers. It has the advantages of reasonable structure, light weight, high production efficiency, low cost, and long service life.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A non-bonded flexible composite pipe includes, from the inside out, a skeleton layer, an inner pressure sealing layer, a pressure-resistant armor layer, a first auxiliary layer, a tensile armor layer, and an outer covering layer. The layers are non-bondedly connected. The inner pressure sealing layer and the outer covering layer are both made of PA11 material. The pressure-resistant armor layer bears the pressure difference between the inside and outside of the pipeline. The first auxiliary layer buffers and isolates the medium transported inside the pipe. The tensile armor layer bears axial tensile force.

[0007] By adopting the above technical solution, both the inner pressure sealing layer and the outer covering layer are made of PA11, which increases the ability of the inner pressure sealing layer and the auxiliary layer to resist the internal pressure of the medium being transported in the hose. Under the premise of ensuring the safety of medium transportation, the design life of the non-bonded flexible composite pipeline is effectively improved. At the same time, the number of tensile armor layers can be reduced, thereby reducing costs while ensuring sufficient tensile strength.

[0008] Furthermore, the skeleton layer is made of interlocking stainless steel strips.

[0009] By adopting the above technical solution, support for the overall structure of the pipeline was achieved.

[0010] Furthermore, the inner pressure sealing layer is made of high-toughness strip of PA11 material.

[0011] By adopting the above technical solution, the conveying medium is sealed.

[0012] Furthermore, the pressure-resistant armor layer is formed by alternating spiral winding of Z-shaped steel.

[0013] By adopting the above technical solution, the pressure difference between the inside and outside of the pipeline can be withstood.

[0014] Furthermore, the tensile armor layer is formed by alternating spiral winding of flat steel strips in both directions.

[0015] By adopting the above technical solution, it is possible to withstand axial tensile force.

[0016] Furthermore, the first auxiliary layer is a PA11 material layer.

[0017] By adopting the above technical solution, friction resistance between the compressive armor layer and the tensile armor layer is achieved.

[0018] Furthermore, a second auxiliary layer is provided between the tensile armor layer and the outer covering layer.

[0019] By adopting the above technical solution, the two auxiliary layers are closely attached to the outside of the skeleton layer and the inner pressure sealing layer, which can achieve the function of buffering and isolating the medium inside the pipe.

[0020] Furthermore, the second auxiliary layer is a PA11 material layer.

[0021] By adopting the above technical solution, PA11 is used for the internal pressure sealing layer, auxiliary layer and outer coating layer, which effectively improves the design life of the non-bonded flexible composite pipeline and can also reduce the number of tensile armor layers to reduce costs.

[0022] Furthermore, the outer coating layer is a PA11 material layer, which is applied to the outermost side by extrusion.

[0023] By adopting the above technical solution, seawater is isolated, metal layer corrosion is prevented, and resistance to seawater corrosion and external friction damage is achieved. Combined with auxiliary layers to enhance corrosion resistance, the service life of the hose is greatly improved.

[0024] In summary, the present invention has the following beneficial effects: The design of the skeleton layer and the internal pressure sealing layer allows for better control of the medium within the pipeline skeleton layer and the internal pressure sealing layer, and also offsets part of the skeleton layer load; all structural layers are non-bonded, ensuring the structural safety of the pipeline under high pressure conditions. By using PA11, the internal pressure sealing layer and auxiliary layer are enhanced to resist the internal pressure of the medium being transported in the hose. PA11 is selected for its high toughness for the outer coating layer, making it suitable for high-pressure medium transportation projects on the seabed. At the same time, it can reduce the number of tensile armor layers, thereby reducing costs while ensuring sufficient tensile strength. The thickness of the two auxiliary layers can be adjusted according to actual processing requirements. The auxiliary layers are closely attached to the skeleton layer and the inner pressure sealing layer, which serve to buffer and isolate the medium inside the pipe. The outer coating layer is used to resist seawater corrosion and external friction damage. Although the cost of PA11 material is relatively high, using PA11 material as the auxiliary layer and outer coating layer can enhance the corrosion resistance of the non-bonded flexible pipe and improve its service life. Attached Figure Description

[0025] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of a non-bonded flexible composite pipe according to the present invention.

[0027] In the diagram, 1 is the skeleton layer; 2 is the inner pressure sealing layer; 3 is the pressure-resistant armor layer; 4 is the first auxiliary layer; 5 is the tensile armor layer; 6 is the second auxiliary layer; and 7 is the outer covering layer. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. These embodiments do not constitute a limitation of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0029] A type of non-bonded flexible composite pipe, such as Figure 1As shown, the pipeline includes, from the inside out, a skeleton layer 1, an inner pressure sealing layer 2, a pressure-resistant armor layer 3, a first auxiliary layer 4, a tensile armor layer 5, a second auxiliary layer 6, and an outer covering layer 7. The layers are non-bonded. The inner pressure sealing layer 2 and the outer covering layer 7 are both made of PA11 material, providing a flexible pipe with both inner and outer coverings made of PA11. Although this increases the cost, it effectively improves the design life of the non-bonded flexible composite pipeline. The pressure-resistant armor layer 3 withstands the pressure difference between the inside and outside of the pipeline, the first auxiliary layer 4 buffers and isolates the medium transported inside the pipe, and the tensile armor layer 5 withstands axial tensile force. The design of the skeleton layer 1 and the internal pressure sealing layer 2 allows for better control of the medium within the pipeline skeleton layer 1 and the internal pressure sealing layer 2, and also offsets part of the load on the skeleton layer 1. All structural layers are non-bonded, ensuring the structural safety of the pipeline under high pressure conditions.

[0030] Among them, such as Figure 1 As shown, the skeleton layer 1 is located on the innermost side of the pipeline and is made of interlocking stainless steel strip. The winding angle of the skeleton layer 1 is 90°. The inner pressure sealing layer 2 is located outside the skeleton layer 1 and is made of high-toughness, high-temperature resistant PA11 material. It can also be obtained by extrusion process and has a thickness of less than 12 mm. The outer covering layer 7 can also be obtained by extrusion process. The pressure-resistant armor layer 3 is formed by alternating forward and reverse spiral winding of Z-shaped steel to withstand the pressure difference between the inside and outside of the pipeline; The tensile armor layer 5 is formed by alternating spiral winding of flat steel strips in both directions, and is used to withstand axial tensile force.

[0031] like Figure 1 As shown, the first auxiliary layer 4 and the second auxiliary layer 6 are PA11 material layers, which can be obtained by extrusion. Their thickness can be adjusted according to actual processing requirements. The first auxiliary layer 4 is used for anti-friction between the two metal layers, the pressure-resistant armor layer 3 and the tensile armor layer 5. The two auxiliary layers are closely attached to the skeleton layer 1 and the inner pressure sealing layer 2, and can also play the role of buffering and isolating the medium inside the pipe. By using PA11, the internal pressure sealing layer 2 and auxiliary layer are enhanced to resist the internal pressure of the medium being transported in the hose. PA11 is selected for its high toughness for the outer covering layer 7, making it suitable for high-pressure medium transportation projects on the seabed. At the same time, it can reduce the number of tensile armor layers 5, thereby reducing costs while ensuring sufficient tensile strength.

[0032] like Figure 1As shown, the outer coating layer 7 is a PA11 material layer, which is extruded onto the outermost side and is used to isolate seawater and prevent corrosion of the metal layer, achieving resistance to seawater corrosion and external friction damage. Combined with auxiliary layers, it enhances corrosion resistance and significantly improves the service life of the hose. Although the cost of PA11 material is relatively high, the use of PA11 material as an auxiliary layer and outer coating layer 7 can enhance the corrosion resistance of the non-bonded flexible hose and improve its service life.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the scope of its essence and protection. Such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A non-bonded flexible composite pipe, characterized in that: It includes, from the inside out, a skeleton layer, an inner pressure sealing layer, a pressure-resistant armor layer, a first auxiliary layer, a tensile armor layer, and an outer covering layer. The layers are non-bonded. The inner pressure sealing layer and the outer covering layer are both made of PA11 material. The pressure-resistant armor layer bears the pressure difference between the inside and outside of the pipeline. The first auxiliary layer buffers and isolates the medium transported in the pipeline. The tensile armor layer bears the axial tensile force.

2. The non-bonded flexible composite tube according to claim 1, characterized in that: The skeleton layer is made of interlocking stainless steel strips.

3. The non-bonded flexible composite tube according to claim 1 or 2, characterized in that: The internal pressure sealing layer is made of high-toughness PA11 material.

4. The non-bonded flexible composite tube according to claim 1, characterized in that: The pressure-resistant armor layer is formed by alternating forward and reverse spiral winding of Z-shaped steel.

5. The non-bonded flexible composite tube according to claim 1 or 4, characterized in that: The tensile armor layer is formed by alternating spiral winding of flat steel strips in both directions.

6. The non-bonded flexible composite tube according to claim 1, characterized in that: The first auxiliary layer is a PA11 material layer.

7. The non-bonded flexible composite tube according to claim 1 or 6, characterized in that: A second auxiliary layer is also provided between the tensile armor layer and the outer covering layer.

8. The non-bonded flexible composite tube according to claim 7, characterized in that: The second auxiliary layer is a PA11 material layer.

9. The non-bonded flexible composite tube according to claim 1, characterized in that: The outer coating layer is a PA11 material layer, which is applied to the outermost side by extrusion.

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