Long-distance conveying pipeline for natural gas

Abstract

The utility model relates to the technical field of natural gas conveying pipelines, and discloses a long-distance natural gas conveying pipeline which comprises a gas conveying pipeline, connecting flanges are arranged at the two ends of the gas conveying pipeline, threaded holes are formed in the two connecting flanges, connecting bolts are installed in the threaded holes, and a sealing groove is formed in the end face of the connecting flange at any end. The end face of the connecting flange at the other end protrudes outwards to form a sealing protrusion matched with the sealing groove, the sealing grooves and the sealing protrusions of the two adjacent gas pipelines are installed in a butt joint mode, the sealing grooves and the sealing protrusions are provided with sealing structures, wedge-shaped tangent planes are formed in the outer edges of the connecting flanges, and the wedge-shaped tangent planes and the threaded holes are distributed in a staggered mode. The wedge-shaped sections of every two adjacent connecting flanges are combined to form a wedge-shaped notch, an opening of each wedge-shaped notch is gradually enlarged from inside to outside in the radial direction, a pressing structure is installed in each wedge-shaped notch, and the lower end of each pressing structure makes contact with the corresponding sealing structure. According to the utility model, the sealing performance of the joint of the underwater gas pipeline is enhanced, and the maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas transmission pipelines, in particular to a long-distance transmission pipeline for natural gas. Background Art

[0002] Most natural gas is transported by pipelines, and a small amount is transported by tankers and other means. A natural gas pipeline refers to a pipeline that transports natural gas from the mining site or processing plant to the urban gas distribution center or industrial enterprise users. It is also called a gas transmission pipeline. For offshore gas fields, the collected natural gas is more efficiently transported through underwater transmission pipelines.

[0003] Due to the high difficulty, high technical requirements and high cost of welding connections in underwater environments, existing underwater gas pipelines usually use flange connections. The sealing performance of the flange-connected gas pipelines at the joints is reduced after long-term service, which is easy to cause natural gas leakage. Maintenance personnel are required to perform frequent maintenance and take sealing remedial measures in a timely manner. In addition, the maintenance of underwater environments is difficult, which reduces the work efficiency of maintenance personnel and increases maintenance costs. Utility Model Content

[0004] The utility model aims to provide a long-distance natural gas transmission pipeline to enhance the sealing performance of the connection of the underwater natural gas transmission pipeline and reduce the labor intensity and cost of leakage inspection and repair.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a long-distance natural gas transmission pipeline, including a gas transmission pipeline, both ends of the gas transmission pipeline are provided with connecting flanges, the two connecting flanges are provided with annular arrays and mutually corresponding threaded holes, connecting bolts are installed in the threaded holes, a sealing groove is provided on the end face of the connecting flange at either end of the gas transmission pipeline, the end face of the connecting flange at the other end protrudes outward to form a sealing protrusion that matches the sealing groove, the sealing grooves and the sealing protrusions of two adjacent gas transmission pipelines are butt-mounted, and a sealing structure is provided at the connection between the sealing grooves and the sealing protrusions, a plurality of wedge-shaped sections are evenly opened on the outer edge of the connecting flange, the wedge-shaped sections are staggered with the threaded holes, the corresponding wedge-shaped sections of the two adjacent connecting flanges are combined into a wedge-shaped notch, the opening of the wedge-shaped notch gradually expands from the inside to the outside along the radial direction, a clamping structure is installed in the wedge-shaped notch, and the lower end of the clamping structure is in contact with the sealing structure.

[0006] The principles and advantages of this solution are:

[0007] 1. In actual application, the natural gas transmission pipeline in this scheme is installed below the sea level at a water depth of more than 50m. A clamping structure is provided on the outside of the sealing structure. The water pressure acts on the end face of the clamping structure and pushes the clamping structure to move along the wedge-shaped notch into the transmission pipeline. When the sealing structure is used for a long time and its performance is aged and deformed, and the seal is not tight, the clamping structure squeezes the sealing structure toward the center of the transmission pipeline under the action of water pressure, so that the overall occupied space of the sealing structure becomes smaller, and the sealing structure expands and deforms to fit more closely with the connecting flanges on both sides, reducing the gap and effectively improving the sealing performance. There is no need to frequently replace the sealing structure, which increases the service life of the sealing structure. At the same time, the water pressure causes the sealing structure to expand and deform, effectively reducing the maintenance frequency of the sealing structure, reducing the work intensity of the maintenance personnel, and effectively reducing the later maintenance costs.

[0008] 2. In this scheme, the connection between two adjacent gas pipelines is butt-mounted through the sealing grooves and sealing protrusions of the two connecting flanges. The sealing grooves and sealing protrusions cooperate to play an installation positioning role, which reduces the difficulty of alignment between the two gas pipelines and enables the threaded holes on the two connecting flanges to be aligned more quickly, thereby improving construction efficiency. At the same time, the connection between the sealing groove and the sealing protrusion is in the shape of a broken line as a whole, so that the sealing structure is in the shape of a broken line as a whole. The multi-angle sealing structure makes the sealing performance of the connection between the two gas pipelines better.

[0009] 3. The design of the sealing groove and the sealing protrusion makes the cross-section of the sealing structure between the two curved as a whole, which increases the contact area between the sealing structure and the connecting flanges on both sides, makes the internal stress of the sealing structure more evenly dispersed, and reduces the stress per unit area, thereby reducing the wear of the sealing structure and effectively extending the service life of the sealing structure.

[0010] Furthermore, the clamping structure is a wedge-shaped clamping block that matches the wedge-shaped notch.

[0011] Under the action of water pressure, the wedge-shaped pressing block moves in the wedge-shaped notch, and the contact surface of the wedge-shaped pressing block and the wedge-shaped notch fits completely, making the two tightly connected, which plays a certain sealing role and also effectively prevents the wedge-shaped pressing block from loosening in the water flow.

[0012] Furthermore, the sealing structure includes a first sealing ring, a second sealing ring and a third sealing ring which are sequentially distributed from the inside to the outside in the radial direction.

[0013] The above setting divides the sealing structure into three independent sealing rings. One is to enable each sealing ring to be replaced separately when it fails, thereby reducing maintenance costs. The other is to make the sealing ring smaller in size and deform more quickly when squeezed in the later stage, so that the sealing performance can be restored faster and more effectively.

[0014] Furthermore, the upper end of the third sealing ring is located in the wedge-shaped notch and the cross-section of the upper end is wedge-shaped.

[0015] The above-mentioned arrangement enables the third sealing ring to contact the clamping structure in the wedge-shaped notch, ensuring that the clamping structure has a distance to move inward in the wedge-shaped notch, and ensuring that when the elasticity of the sealing structure is reduced and the seal is not tight, the clamping structure can squeeze the sealing structure inward under the action of water pressure, causing the sealing structure to expand and deform, restore the sealing performance, and improve the overall service life of the sealing structure.

[0016] Furthermore, two adjacent connecting flanges are provided with a plurality of limiting grooves in an annular array along the circumferential direction, and each limiting groove includes an annular through groove and a plurality of mounting openings in an annular array with the central axis of the wedge-shaped notch as the axis, and the mounting openings are located on the outside of the annular through groove and are connected to the annular through groove, and a limiting structure for limiting the outward movement of the clamping structure is installed in the limiting groove.

[0017] The purpose of the above-mentioned mounting port and annular groove design is to utilize the structure of the gas pipeline and the connecting flange itself to achieve the fixation of the limiting structure, minimize the connection and fixing relationship achieved by other components, so as to reduce the loosening of the connection structure in the underwater environment, and make the connection between the gas pipelines more firm and reliable.

[0018] Furthermore, the limiting structure includes a hollow limiting ring and limiting strips evenly distributed along the outer circumference of the limiting ring, and the limiting ring is located in the wedge-shaped notch.

[0019] The above-mentioned arrangement realizes the overall fixation of the limiting structure by entering from the installation port through the limiting strip and rotating in the annular through groove to fall into the fixing groove. At the same time, the limiting ring is located in the wedge-shaped notch and fixed above the clamping structure to avoid the outside of the clamping structure from shaking in the water flow and escaping from the wedge-shaped notch due to the lack of limiting measures. The annular structure of the limiting ring will not occupy too much of the upper end surface of the clamping structure, thereby effectively ensuring the water pressure action area.

[0020] Furthermore, the limiting notch also includes a plurality of fixing grooves in a circular array with the central axis of the wedge-shaped notch as the axis, the fixing grooves are located inside the annular through groove and are connected to the annular through groove, and the fixing grooves and the mounting openings are staggered.

[0021] The purpose of setting the above-mentioned fixing groove is to prevent the flow and impact of water when the gas pipeline is working underwater, which may cause the limiting structure to rotate by itself in the annular groove. When the limiting strip is rotated to the position of the installation port, it is easy to fall off from the installation port, resulting in the failure of the limiting effect of the limiting structure on the clamping structure. There is a risk of the clamping structure being separated from the pipeline, which in turn leads to reduced sealing performance and natural gas leakage. The limiting structure rotates in the annular groove and causes the limiting strip to fall into the fixing groove. The fixing groove limits the circumferential movement of the limiting strip, which has a better limiting effect on the clamping structure.

[0022] Furthermore, an inwardly concave arc groove is formed on the upper end surface of the wedge-shaped pressing block.

[0023] In the above arrangement, the arc groove increases the contact area between water and the compression structure, the water pressure acts on the wedge-shaped compression block with greater pressure, and then indirectly acts on the sealing structure with greater pressure, and the sealing structure is squeezed, expanded and deformed more obviously.

[0024] Furthermore, a natural gas leakage sensor is provided at the bottom of the wedge-shaped pressing block.

[0025] When the compression structure can no longer enhance the sealing performance by squeezing the sealing structure, the sealing structure fails and natural gas leaks out. The natural gas leakage sensor detects the change in natural gas concentration and transmits the sensing signal to the receiving terminal for early warning. Maintenance personnel conduct timely maintenance based on the early warning signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0027] Figure 2 for Figure 1 Enlarged view of part B.

[0028] Figure 3 for Figure 1 Right side view of the gas pipeline on the left.

[0029] Figure 4 for Figure 3 Cross-sectional view along AA direction.

[0030] Figure 5 for Figure 4 Magnified view of part C.

[0031] Figure 6 for Figure 5 Enlarged view of part D.

[0032] Figure 7 It is a top view of the limiting structure in the first embodiment.

[0033] Figure 8 It is a front view of the limiting structure in the first embodiment.

[0034] Fig. 9 It is a schematic diagram of the local structure of the second embodiment.

[0035] Fig.10 for Fig. 9 Cross-sectional view along EE direction

[0036] Fig.11 for Fig.10 Cross-sectional view along the FF direction.

[0037] Fig.12 This is a schematic diagram of the structure of the third embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following is further described in detail through specific implementation methods:

[0039] The figure marks in the drawings of the specification include: gas transmission pipeline 1, connecting flange 2, connecting bolts 3, sealing groove 4, sealing protrusion 5, sealing structure 6, first sealing ring 61, second sealing ring 62, third sealing ring 63, wedge-shaped notch 7, clamping structure 8, limiting notch 9, installation port 91, annular through groove 92, fixing groove 93, limiting structure 10, limiting ring 101, limiting strip 102, rotating handle 103, natural gas leakage sensor 11.

[0040] Example 1 Basic information is as shown in the attached Figure 1-8 As shown:

[0041] like Figure 1-5 As shown in combination, a long-distance natural gas transmission pipeline includes a gas pipeline 1, both ends of the gas pipeline 1 are provided with connecting flanges 2, and both connecting flanges 2 are provided with threaded holes in an annular array and corresponding to each other, and connecting bolts 3 are installed in the threaded holes. A sealing groove 4 is provided on the end face of the connecting flange 2 at either end of the gas pipeline 1, and the end face of the connecting flange 2 at the other end protrudes outward to form a sealing protrusion 5 that matches the sealing groove 4. The sealing grooves 4 and sealing protrusions 5 of two adjacent gas pipelines 1 are docked and installed, and the sealing grooves 4 and sealing protrusions 5 cooperate to play a role in installation and positioning, which reduces the difficulty of alignment and effectively improves work efficiency; the sealing grooves 4 and sealing protrusions 5 of the two adjacent gas pipelines 1 are provided with a sealing structure 6, and the connection between the sealing grooves 4 and the sealing protrusions 5 is in the shape of a broken line as a whole, so that the cross-section of the sealing structure 6 is in the shape of a broken line as a whole, and the multi-angle sealing structure 6 makes the sealing performance of the connection between the two gas pipelines 1 better. Figure 1 , Figure 2 , Figure 5 and Figure 6As shown in the figure, a plurality of wedge-shaped sections are evenly opened at the outer edge of the end face of the connecting flange 2, and the wedge-shaped sections are staggered with the threaded holes. The corresponding wedge-shaped sections of two adjacent connecting flanges 2 are combined into a wedge-shaped notch 7, and the wedge-shaped notch 7 is located between the two adjacent threaded holes. The opening of the wedge-shaped notch 7 gradually expands from the inside to the outside along the radial direction of the gas pipeline 1. A clamping structure 8 is installed in the wedge-shaped notch 7, and the lower end of the clamping structure 8 is in contact with the sealing structure 6. The clamping structure 8 is a wedge-shaped clamping block matched with the wedge-shaped notch 7; in an underwater environment, the water pressure acts on On the upper surface of the clamping structure 8, the clamping structure 8 is pushed to move along the inside of the gas pipeline 1, squeezing the sealing structure 6, so that the sealing structure 6 expands and contacts more closely with the connecting flanges 2 on both sides, effectively enhancing the sealing performance of the connection between the two gas pipelines 1; preferably, an inwardly concave arc groove is opened on the upper end surface of the wedge-shaped clamping block, and the arc groove makes the contact area between the wedge-shaped clamping block and water larger, the pressure of the water pressure acting on the wedge-shaped clamping block is greater, and then the pressure indirectly acting on the sealing structure 6 is greater, and the sealing structure 6 is squeezed, expanded and deformed more obviously.

[0042] like Figure 4-Figure 6 As shown in the figure, the sealing structure 6 includes a first sealing ring 61, a second sealing ring 62 and a third sealing ring 63 which are distributed in sequence from the inside to the outside along the radial direction. The multiple separate sealing rings make the upper end of the third sealing ring 63 protrude upward and be located in the wedge-shaped notch 7, and the upper end cross-section is wedge-shaped and tightly attached to the inner wall of the wedge-shaped notch 7. This can effectively ensure that when water pressure acts on the clamping structure 8, the clamping structure 8 can immediately act on the sealing structure 6 and squeeze the sealing structure 6 toward the center of the gas pipeline 1, so that the sealing structure 6 expands and deforms, and the sealing performance is enhanced.

[0043] like Figure 1 , Figure 2 As shown in the figure, the clamping structure 8 is evenly arranged along the circumference of the connecting flange 2. To prevent the clamping structure 8 from being separated from the wedge-shaped notch 7 under the impact of water flow, a plurality of limiting notches 9 in an annular array are formed along the circumference of two adjacent connecting flanges 2. The position and number of the limiting notches 9 correspond to those of the wedge-shaped notch 7. Figure 2 , Figure 3 , Figure 7-9 As shown in the combination, each limiting slot 9 includes an annular through slot 92 and a plurality of mounting openings 91. The mounting openings 91 are arranged in an annular array with the central axis of the wedge-shaped notch 7 as the axis. The mounting openings 91 are located outside the annular through slot 92 and are connected to the annular through slot 92. The mounting openings 91 and the annular through slot 92 are connected to the wedge-shaped notch 7 through a conical notch. A limiting structure 10 for limiting the outward movement of the clamping structure 8 is installed in the limiting slot 9, as shown in FIG. Figure 6-Figure 8As shown in the figure, the limiting structure 10 includes a hollow limiting ring 101, and a plurality of limiting strips 102 are evenly distributed along the circumference of the limiting ring 101, and the limiting strips 102 are corresponding to the installation opening 91 one by one. The limiting strips 102 protrude toward the surroundings, and the limiting ring 101 is located in the wedge-shaped notch 7. Since the overall volume of the limiting structure 10 is relatively small, in order to facilitate workers to install and disassemble the limiting structure 10, a plurality of vertical rotating handles 103 are evenly arranged on the limiting ring 101, and the uppermost end of the rotating handle 103 protrudes from the surface of the connecting flange 2, so that it is convenient for workers to realize the rotation and placement of the limiting structure 10 by rotating the handle 103. When in use, align the limiting strip 102 on the limiting ring 101 with the installation opening 91 so that the limiting strip 102 enters the annular through groove 92, and rotate the limiting structure 10 so that the limiting strip 102 is misaligned with the installation opening 91, and the limiting structure 10 is limited by the connecting flange 2, and the limiting structure 10 realizes the function of limiting the clamping structure 8.

[0044] Embodiment 2

[0045] Compared with the embodiment, the present embodiment is different in that: Figure 9-11 As shown in combination, in this embodiment, the limiting notch 9 also includes a plurality of fixing grooves 93, and the fixing grooves 93 are arranged in a circular array with the central axis of the wedge-shaped notch 7 as the axis, and the installation opening 91 and the fixing grooves 93 are staggered. The installation opening 91 and the fixing grooves 93 are respectively located on the outside and inside of the annular through groove 92 and are connected to the annular through groove 92. The purpose of setting the fixing grooves 93 is to prevent the limiting structure from not being circumferentially fixed in the annular through groove 91. When the gas pipeline 1 is working underwater, the flow and impact of the water flow may cause the limiting structure 10 to rotate in the annular through groove 91. When the limiting strip 102 rotates to the position of the installation opening 91, it is easy to fall off from the installation opening 91, resulting in the failure of the limiting effect of the limiting structure 10 on the clamping structure 8. There is a risk that the clamping structure 8 will be separated from the pipeline, which will lead to reduced sealing performance and natural gas leakage.

[0046] During specific use, the limiting strip 102 on the limiting ring 101 is aligned with the installation opening 91 so that the limiting strip 102 enters the annular groove 92, and then the limiting ring 101 is rotated to make the limiting strip 102 fall into the fixing groove 93. In order to prevent the limiting structure 10 located vertically below the gas pipeline 1 from falling off, an annular metal block is installed in the annular groove 92 located directly below so that the limiting structure 10 is compressed. Through the above arrangement, the limiting structure 10 is restricted by the connecting flange 2, and the limiting structure 10 realizes the function of restricting the clamping structure 8.

[0047] Embodiment 3

[0048] like Fig.12As shown, in this embodiment, a natural gas leakage sensor 11 is embedded and installed at the bottom of the wedge-shaped compression block. The natural gas leakage sensor 11 is an electrochemical sensor. When the compression structure 8 cannot enhance the sealing performance by squeezing the sealing structure 6 again, the sealing structure 6 fails and the natural gas leaks out. The natural gas leakage sensor 11 detects the change in natural gas concentration and transmits the sensing signal to the receiving terminal for early warning. The maintenance personnel perform timely maintenance according to the early warning signal.

[0049] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A long-distance natural gas transmission pipeline, comprising a gas transmission pipeline, both ends of which are provided with connecting flanges, both connecting flanges are provided with circular arrays of threaded holes corresponding to each other, and connecting bolts are installed in the threaded holes, characterized in that: A sealing groove is provided on the end surface of the connecting flange at either end of the gas pipeline, and the end surface of the connecting flange at the other end protrudes outward to form a sealing protrusion matching the sealing groove. The sealing grooves and sealing protrusions of two adjacent gas pipelines are butt-jointed and installed, and a sealing structure is provided at the connection between the sealing grooves and the sealing protrusions. A plurality of wedge-shaped sections are evenly arranged on the outer edge of the connecting flange, and the wedge-shaped sections are staggered with the threaded holes. The corresponding wedge-shaped sections of the two adjacent connecting flanges are combined into a wedge-shaped notch, and the opening of the wedge-shaped notch gradually expands from the inside to the outside along the radial direction. A clamping structure is installed in the wedge-shaped notch, and the lower end of the clamping structure is in contact with the sealing structure.

2. A long-distance natural gas transmission pipeline according to claim 1, characterized in that: The clamping structure is a wedge-shaped clamping block matched with the wedge-shaped notch.

3. A long distance natural gas transmission pipeline according to claim 2, characterized in that: The sealing structure comprises a first sealing ring, a second sealing ring and a third sealing ring which are sequentially distributed from the inside to the outside in the radial direction.

4. A long-distance natural gas transmission pipeline according to claim 3, characterized in that: The upper end of the third sealing ring is located in the wedge-shaped notch and the cross section of the upper end is wedge-shaped.

5. A long-distance natural gas transmission pipeline according to claim 4, characterized in that: Two adjacent connecting flanges are provided with a plurality of limiting grooves in an annular array along the circumferential direction. Each limiting groove includes an annular through groove and a plurality of mounting openings in an annular array with the central axis of the wedge-shaped notch as the axis. The mounting openings are located on the outside of the annular through groove and are connected to the annular through groove. A limiting structure for limiting the outward movement of the clamping structure is installed inside the limiting groove.

6. A long distance natural gas transmission pipeline according to claim 5, characterized in that: The limiting structure comprises a hollow limiting ring and limiting strips evenly distributed along the outer circumference of the limiting ring, and the limiting ring is located in the wedge-shaped notch.

7. A long distance natural gas transmission pipeline according to claim 6, characterized in that: The limiting notch also includes a plurality of fixing grooves in an annular array with the central axis of the wedge-shaped notch as the axis. The fixing grooves are located on the inner side of the annular through groove and are connected to the annular through groove. The fixing grooves and the installation notches are staggered.

8. A long-distance natural gas transmission pipeline according to claim 7, characterized in that: An inwardly concave arc groove is formed on the upper end surface of the wedge-shaped pressing block.

9. A long-distance natural gas transmission pipeline according to claim 8, characterized in that: A natural gas leakage sensor is arranged at the bottom of the wedge-shaped pressing block.

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