Method and system for reducing stress in long pipelines
By determining the curvature radius and angle of hot-bent pipes and combining them with cold-bent pipes, the problems of high difficulty and high risk in the construction of long-distance pipelines were solved, and the stress level was reduced and the construction was simplified.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-07-24
AI Technical Summary
Existing technologies for reducing stress in long-distance pipelines are difficult to implement, carry high risks, increase the number of approvals and the risk of weld defects, affect the pipeline route, and are difficult to procure and construct.
By determining whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature under the condition of meeting the stress requirements of long-distance pipelines, if it is greater, hot-bent pipes are used; if it is less, combined cold-bent pipes are used. The angle of the hot-bent pipes is adjusted to meet the preset path direction, and the number and radius of curvature of the cold-bent pipes are calculated to form a long-distance pipeline.
It simplifies the construction process, reduces the stress risk of long-distance pipelines, keeps the pipeline route unchanged, reduces the difficulty of procurement and construction, and avoids the risks and complexities of conventional practices.
Smart Images
Figure CN122452956A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pipeline technology, and in particular to a method and system for reducing stress in long-distance pipelines. Background Technology
[0002] Analyzing the components of long-distance pipelines, they mainly include straight pipe sections, cold-bent bends, and hot-bent bends. Cold-bent bends and hot-bent bends are primarily used to adjust the burial depth and direction of the pipeline. The difference between the two is: cold-bent bends are typically manufactured on-site without heating, bending straight pipes with a radius of curvature not less than 40 times the pipe diameter, complying with the requirements of the "Code for Fabrication and Acceptance of Cold-Bent Steel Pipes" (SY / T 4127), and their wall thickness is basically the same as the original main pipe; hot-bent bends are manufactured in the factory under induction heating conditions, typically with a radius of curvature not less than 5 times the pipe diameter, complying with the requirements of the "Steel Induction Heated Bends for Oil and Gas Transportation" (SY / T 5257), and their outer arc side wall thickness is less than that of the original main pipe. Ensuring the safety of long-distance pipelines has always been a key point in the oil and gas pipeline industry. An effective approach is to verify the stress of the long-distance pipeline, ensuring that the stress of each component is less than the standard requirements.
[0003] In the stress verification process of long-distance pipelines, the stress of hot-bent pipes often exceeds the standard requirements. From a material perspective, the factors affecting the stress of hot-bent pipes include steel strength, wall thickness, and radius of curvature. Under certain process conditions, wall thickness is inversely proportional to steel strength (stress). However, simply increasing the wall thickness will increase project investment and carbon emissions throughout the entire project chain. Therefore, adjusting the wall thickness and steel grade to reduce stress is not the optimal approach. The method for determining the radius of curvature of hot-bent pipes is usually based on empirical methods, combined with past project experience and factory production conditions. This typically involves adjusting construction parameters (e.g., installation temperature) or design angles and design radii of curvature until the stress of the hot-bent pipe meets the standard requirements.
[0004] However, the above methods have the following problems: First, adjusting the construction parameters of long-distance pipelines is a supplementary measure considering the external environment, and it will increase the difficulty of construction and quality management. In actual implementation, there will inevitably be areas where supervision is inadequate, posing certain hidden dangers. Second, adjusting the design angle of long-distance pipelines will affect the pipeline route, involving regulations and engineering approval procedures, and will also increase the number of pipeline welds. Even if the stress of the long-distance pipeline is reduced, it will bring increased approval processes and weld hazard risks. Third, adjusting the curvature radius of hot-bent pipes exceeds the factory's capacity, making production impossible. Summary of the Invention
[0005] This invention provides a method and system for reducing stress in long-distance pipelines, which can solve the problems in the background art such as high construction difficulty and risk, increased approval times and weld seam risks, affecting the route of long-distance pipelines, and high procurement and construction difficulty in actual implementation.
[0006] On one hand, the present invention provides a method for reducing stress in long-distance pipelines, the method comprising:
[0007] Step 101: Obtain the maximum radius of curvature for hot-bent pipes manufactured in the factory;
[0008] Step 102: Obtain the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline;
[0009] Step 103: Determine whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines;
[0010] Step 104: If so, the long-distance pipeline is formed by hot bending of the pipe.
[0011] Step 105: If not, then use combined cold-bent pipes to form the long-distance pipeline.
[0012] In an optional embodiment, the method further includes: obtaining the angle of the hot-bent tube;
[0013] Based on the angle of the hot-bent pipe and the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline, it is determined whether the actual arc direction of the hot-bent pipe meets the preset path direction.
[0014] If yes, proceed to step 103; otherwise, adjust the angle of the hot-bent tube until the actual arc of the hot-bent tube meets the preset path direction, then proceed to step 103.
[0015] In one optional embodiment, the step of determining whether the actual arc direction of the hot-bent pipe meets the preset path direction includes:
[0016] Obtain the first maximum distance B, whereby the arc direction of the hot-bent pipe deviates from the preset path under the condition that the stress requirements of the long-distance pipeline are met;
[0017] Obtain the second maximum distance W from the actual arc direction of the hot-bent pipe to the preset path;
[0018] Determine whether the second maximum distance W is greater than the first maximum distance B;
[0019] If not, adjust the angle of the hot-bent tube until the actual arc of the hot-bent tube meets the preset path. If yes, determine that the actual arc of the hot-bent tube meets the preset path.
[0020] In an optional embodiment, the first maximum distance that the arc of the hot-bent pipe deviates from the preset path is obtained by the following formula:
[0021] B = R e (1 / cos(0.5α)-1)
[0022] Among them, R e The minimum radius of curvature of the hot-bent pipe is defined as the minimum radius of curvature required to meet the stress requirements of the long-distance pipeline. α is the angle of the hot-bent pipe, and B is the first maximum distance by which the arc of the hot-bent pipe deviates from the preset path.
[0023] In an optional embodiment, step 105 includes:
[0024] Obtain the number of cold-bent bends, the angle of each cold-bent bend, and the radius of curvature of each cold-bent bend;
[0025] The required combination of cold-bent bends to form the long-distance pipeline is determined based on the number of cold-bent bends, the angle of each cold-bent bend, and the radius of curvature of each cold-bent bend.
[0026] In one optional embodiment, obtaining the number of cold-bent bends includes:
[0027] Obtain the arc length of the hot-bent pipe under the minimum radius of curvature required to meet the stress requirements of the long-distance pipeline, and obtain the minimum length of the main pipe for making a single cold-bent pipe.
[0028] The number of cold-bent pipes is determined based on the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines, the arc length of the hot-bent pipe, and the minimum length of the main pipe for making a single cold-bent pipe.
[0029] In one optional embodiment, the number of cold-bent bends is obtained using the following formula:
[0030]
[0031] Where n is the number of cold-bent pipes, L pr To determine the arc length of a hot-bent bend under the minimum radius of curvature required to meet the stress requirements of long-distance pipelines, L s Minimum length of the main pipe for making a single cold-bent pipe.
[0032] In one optional embodiment, obtaining the angle of the cold-bent pipe includes: obtaining the angle of the hot-bent pipe;
[0033] The angle of the cold-bent tube is determined based on the angle of the hot-bent tube and the number of cold-bent tubes.
[0034] In one alternative embodiment, the angle of the single cold-bent bend is obtained by the following formula:
[0035]
[0036] Where, β c α is the angle of a single cold-bent pipe, n is the angle of the hot-bent pipe, and n is the number of cold-bent pipes.
[0037] In one optional embodiment, obtaining the radius of curvature of a single cold-bent bend includes:
[0038] The radius of curvature of the single cold-bent pipe is obtained based on the angle of the single cold-bent pipe, the minimum length of the main pipe used to make the single cold-bent pipe, and the minimum length of the straight pipe sections on both sides of the cold-bent pipe body.
[0039] In an alternative embodiment, the radius of curvature of the single cold-bent bend is obtained by the following formula:
[0040]
[0041] Among them, R cu Let β be the radius of curvature of a single cold-bent pipe. c For the angle of a single cold-bent pipe, L s The minimum length of the main pipe for making a single cold-bent bend is denoted by 'a', which represents the minimum length of the straight pipe sections on both sides of the cold-bent bend body.
[0042] In one optional embodiment, the combination of cold-bent bends required to form the long-distance pipeline is determined based on the number of cold-bent bends, the angle of each individual cold-bent bend, and the radius of curvature of each individual cold-bent bend, including:
[0043] Determine the angle of a single cold-bent pipe and the maximum angle that can be used to make cold-bent pipes; determine the radius of curvature of a single cold-bent pipe and the minimum radius of curvature that can be used to make cold-bent pipes.
[0044] If the angle of a single cold-bent pipe is less than the maximum angle that can be used to make a cold-bent pipe, and the radius of curvature of a single cold-bent pipe is greater than the minimum radius of curvature that can be used to make a cold-bent pipe, then the number, angle, and radius of curvature of the combined cold-bent pipes that need to be combined to form the long-distance pipeline are determined based on the number of cold-bent pipes, the angle of a single cold-bent pipe, and the radius of curvature of a single cold-bent pipe.
[0045] On the other hand, a system for reducing stress in long-distance pipelines is provided, including a processor and a memory, the memory storing a computer program that, when executed by the processor, performs the following process:
[0046] Step 101: Obtain the maximum radius of curvature for hot-bent pipes manufactured in the factory;
[0047] Step 102: Obtain the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline;
[0048] Step 103: Determine whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines;
[0049] Step 104: If so, the long-distance pipeline is formed by hot bending of the pipe.
[0050] Step 105: If not, then use combined cold-bent pipes to form the long-distance pipeline.
[0051] Compared with existing technologies, the advantages of this invention are that it avoids the conventional practice of adjusting construction parameters (e.g., installation temperature) and the design angle and radius of curvature of hot-bent pipes during the construction of long-distance pipelines. By determining whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline, if the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline, then hot-bent pipes are used to form the long-distance pipeline. If the maximum radius of curvature of the hot-bent pipe manufactured in the factory is less than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline, then combined cold-bent pipes are used to form the long-distance pipeline. The engineering measures are simple and easy to implement, keeping the stress of the long-distance pipeline at a low level, reducing the stress risk of the long-distance pipeline, while not affecting the route of the long-distance pipeline, and also reducing the difficulty of procurement and construction. Attached Figure Description
[0052] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.
[0053] Figure 1 This is a schematic flowchart of a method for reducing stress in long-distance pipelines according to an embodiment of the present invention.
[0054] Figure 2 This is a schematic diagram of step S105 in the method for reducing stress in long-distance pipelines according to an embodiment of the present invention.
[0055] Figure 3 This is a schematic diagram of the overall process of a method for reducing stress in long-distance pipelines according to an embodiment of the present invention.
[0056] Figure 4 This is a stress distribution diagram before adjusting the radius of curvature of the hot-bent pipe in an embodiment of the present invention.
[0057] Figure 5 This is a stress distribution diagram after adjusting the radius of curvature of the hot-bent pipe in an embodiment of the present invention.
[0058] Figure 6 This is a diagram showing that the arc at IP0403 in an embodiment of the present invention meets the preset path requirements.
[0059] Figure 7 This is a diagram showing that the arc at IP0404 in an embodiment of the present invention meets the preset path requirements. Detailed Implementation
[0060] The invention will now be further described with reference to the accompanying drawings.
[0061] The long-distance pipelines provided in this invention mainly include straight pipe sections, cold-bent bends, and hot-bent bends. In this invention, a hot-bent bend is obtained by heating the pipeline to a certain temperature and then bending it; the hot-bent bend includes straight pipe sections and bent pipe sections. A cold-bent bend is formed by bending the pipeline using external force without heating it.
[0062] Please see Figure 1 , Figure 1 This is a schematic flowchart of a method for reducing stress in long-distance pipelines according to the present invention. The method includes the following steps:
[0063] Step 101: Obtain the maximum radius of curvature for hot-bent pipes manufactured in the factory;
[0064] Step 102: Obtain the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline;
[0065] Step 103: Determine whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines;
[0066] Step 104: If so, hot bending is used to form a long-distance pipeline;
[0067] Step 105: If not, then use combined cold-bent pipes to form a long-distance pipeline.
[0068] The advantage of this invention lies in avoiding the conventional practice of adjusting construction parameters (e.g., installation temperature) and the design angle and radius of curvature of hot-bent pipes during the construction of long-distance pipelines. It determines whether the maximum radius of curvature of the factory-made hot-bent pipe is greater than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline. If the maximum radius of curvature of the factory-made hot-bent pipe is greater than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline, then hot-bent pipes are used to form the long-distance pipeline. If the maximum radius of curvature of the factory-made hot-bent pipe is less than the minimum radius of curvature of the hot-bent pipe under the stress requirements of the long-distance pipeline, then combined cold-bent pipes are used to form the long-distance pipeline. The engineering measures are simple and easy to implement, keeping the stress of the long-distance pipeline at a low level, reducing the stress risk of the long-distance pipeline, and not affecting the route of the long-distance pipeline, while also reducing the difficulty of procurement and construction.
[0069] In one optional embodiment, the method provided by the present invention further includes: obtaining the angle of the hot-bent pipe;
[0070] The actual arc direction of the hot-bent pipe is judged based on the angle of the hot-bent pipe and the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline.
[0071] If yes, proceed to step 103; otherwise, adjust the angle of the hot-bent tube until the actual arc of the hot-bent tube meets the preset path direction, then proceed to step 103.
[0072] It is understandable that route selection is performed first during the design of long-distance pipeline systems, i.e., the preset path direction described in this embodiment of the invention. If the actual arc direction of the hot-bent pipe meets the preset path direction, then step 103 is executed, i.e., determining whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline.
[0073] It should be noted that the deviation of the arc direction of the hot-bent pipe from the preset path at the same angle is proportional to the radius of curvature; that is, the larger the required radius of curvature of the bend, the greater the deviation distance. Therefore, in this embodiment of the invention, before determining whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline, it is also determined whether the actual direction of the hot-bent pipe meets the direction of the preset path. Under the premise that the actual direction of the hot-bent pipe meets the direction of the preset path, step 103 is executed, that is, determining whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline, and then determining whether to use a combination of cold-bent pipes to form a long-distance pipeline, and whether the route of the combined line meets the preset path requirements.
[0074] In one optional embodiment, the step of determining whether the actual arc direction of the hot-bent pipe meets the preset path direction includes: obtaining the first maximum distance B of the arc direction of the hot-bent pipe deviating from the preset path under the condition of meeting the stress requirements of the long-distance pipeline;
[0075] Obtain the second maximum distance W from the actual arc direction of the hot-bent pipe to the preset path;
[0076] Determine whether the second maximum distance W is greater than the first maximum distance B;
[0077] If not, adjust the angle of the hot-bending pipe until the actual arc direction of the hot-bending pipe meets the preset path direction; if yes, confirm that the actual arc direction of the hot-bending pipe meets the preset path direction.
[0078] This invention obtains the first maximum distance B, where the arc direction of the hot-bent pipe deviates from the preset path, and the second maximum distance W, where the actual arc direction of the hot-bent pipe deviates from the preset path, under the condition of meeting the stress requirements of the long-distance pipeline. By determining whether the second maximum distance W is greater than the first maximum distance B, it can be determined whether the hot-bent pipe has deviated from the preset path. Then, the actual arc direction of the hot-bent pipe can be adjusted, that is, the installation direction or the angle of the hot-bent pipe can be adjusted, thereby adjusting the distance between the long-distance pipeline formed by the hot-bent pipe and the preset path, ensuring that the installation of the long-distance pipeline does not deviate from the preset path.
[0079] In an optional embodiment, the first maximum distance that the arc of the hot-bent pipe deviates from the preset path is obtained by the following formula:
[0080] B = R e (1 / cos(0.5α)-1)
[0081] Among them, R e Let α be the minimum radius of curvature of the hot-bent pipe while meeting the stress requirements of the long-distance pipeline, and let B be the first maximum distance that the arc direction of the hot-bent pipe deviates from the preset path.
[0082] Furthermore, the second maximum distance W can be obtained through actual measurement of the design documents. (Reference) Figure 6 , Figure 6 The direction of the land acquisition area can be understood as the preset path direction of the present invention. The second maximum distance W can be obtained by manually measuring the distance between the hot-burning bend and the boundary of the land acquisition area.
[0083] Please see Figure 2 In one optional embodiment, step 105 includes steps 1051, 1052, 1053 and 1054.
[0084] Step 1051: Obtain the number of cold-bent pipes; Step 1052: Obtain the angle of a single cold-bent pipe; Step 1053: Obtain the radius of curvature of a single cold-bent pipe; Step 1054: Based on the number of cold-bent pipes, the angle of a single cold-bent pipe, and the radius of curvature of a single cold-bent pipe, determine the combined cold-bent pipes needed to form a long-distance pipeline.
[0085] It should be noted that, in this embodiment of the invention, the long-distance pipeline includes a combination of multiple hot-bent and cold-bent pipes. Therefore, if the maximum radius of curvature of the hot-bent pipe manufactured in the factory is less than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline, it is necessary to replace the hot-bent pipe with a combination of cold-bent pipes. That is, it is necessary to determine the number of cold-bent pipes, the angle of a single cold-bent pipe, and the radius of curvature of a single cold-bent pipe, and then determine the combination of cold-bent pipes that need to be combined to form the long-distance pipeline.
[0086] The cold-bent pipe includes a bent pipe section and straight pipe sections connected to both ends of the bent pipe section. The included angle between the two straight pipe sections is the angle of the cold-bent pipe provided in the embodiment of the present invention.
[0087] Accordingly, the hot-bending pipe includes a bent pipe section and straight pipe sections connected to both ends of the bent pipe section, and the included angle between the two straight pipe sections is the angle of the hot-bending pipe provided in the embodiment of the present invention.
[0088] In one optional embodiment, obtaining the number of cold-bent pipes includes: obtaining the arc length of the hot-bent pipe under the minimum radius of curvature of the hot-bent pipe that meets the stress requirements of the long-distance pipeline; obtaining the minimum length of the parent pipe for making a single cold-bent pipe; and determining the number of cold-bent pipes based on the arc length of the hot-bent pipe under the minimum radius of curvature of the hot-bent pipe that meets the stress requirements of the long-distance pipeline and the minimum length of the parent pipe for making a single cold-bent pipe.
[0089] In one optional embodiment, the number of cold-bent bends is obtained using the following formula:
[0090]
[0091] Where n is the number of cold-bent bends, L pr To determine the arc length of a hot-bent bend under the minimum radius of curvature required to meet the stress requirements of long-distance pipelines, L s Minimum length of the main pipe for making a single cold-bent pipe.
[0092] In one alternative embodiment, obtaining the angle of a single cold-bent pipe includes: obtaining the angle of a hot-bent pipe;
[0093] The angle of a single cold-bent pipe is determined based on the angle of the hot-bent pipe and the number of cold-bent pipes.
[0094] In one alternative embodiment, the angle of a single cold-bent bend is obtained using the following formula:
[0095]
[0096] Where, β c α represents the angle of a single cold-bent pipe, α represents the angle of a hot-bent pipe, and n represents the number of cold-bent pipes.
[0097] In one optional embodiment, obtaining the radius of curvature of a single cold-bent bend includes:
[0098] The radius of curvature of a single cold-bent pipe is obtained based on the angle of a single cold-bent pipe, the minimum length of the main pipe used to make a single cold-bent pipe, and the minimum length of the straight pipe sections on both sides of the cold-bent pipe body.
[0099] In an alternative embodiment, the radius of curvature of a single cold-bent bend is obtained using the following formula:
[0100]
[0101] Among them, R cu Let β be the radius of curvature of a single cold-bent pipe. c For the angle of a single cold-bent pipe, L s The minimum length of the main pipe for making a single cold-bent bend is denoted by 'a', which represents the minimum length of the straight pipe sections on both sides of the cold-bent bend body.
[0102] In one optional embodiment, the combination of cold-bent bends for forming long-distance pipelines is determined based on the number of cold-bent bends, the angle of a single cold-bent bend, and the radius of curvature of a single cold-bent bend, including: determining the angle of a single cold-bent bend and the size of the maximum angle that can be used to make a cold-bent bend, and determining the radius of curvature of a single cold-bent bend and the size of the minimum radius of curvature that can be used to make a cold-bent bend.
[0103] If the angle of a single cold-bent pipe is less than the maximum angle that can be used to make a cold-bent pipe, and the radius of curvature of a single cold-bent pipe is greater than the minimum radius of curvature that can be used to make a cold-bent pipe, then the number, angle, and radius of curvature of the combined cold-bent pipes that need to be combined to form the long-distance pipeline are determined based on the number of cold-bent pipes, the angle of a single cold-bent pipe, and the radius of curvature of a single cold-bent pipe.
[0104] Furthermore, comparing the angle of a single cold-bent pipe with the maximum angle that can be used to manufacture cold-bent pipes, at the angle β of the cold-bent pipe... c Less than the maximum angle β that can be used to make cold-bent pipes M , i.e. β c <β M And the radius of curvature R of the cold-bent pipe cu Greater than the minimum radius of curvature R that can be used to make cold-bent pipes c Rcu >R c In this case, the number of cold-bent pipes can be obtained based on the minimum length of the main pipe for making a single cold-bent pipe and the arc length of the hot-bent pipe that meets the stress requirements of the long-distance pipeline, that is, the number of cold-bent pipes n.
[0105] Please continue reading Figure 3 , Figure 3 A system flowchart of a method for reducing stress in long-distance pipelines provided in an embodiment of the present invention.
[0106] Figure 3 In step S1: Obtain the maximum radius of curvature R of the hot-bent pipe manufactured in the factory. h The minimum radius of curvature Re, outer diameter D, and bending angle α of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines; the second maximum distance W of the actual arc direction of the hot-bent pipe deviating from the preset path; and the minimum length L of the main pipe for making a single cold-bent pipe. s The maximum angle β that can be used to make cold-bent pipes M Minimum radius of curvature R c The minimum length 'a' of the straight pipe sections on both sides of the cold-bent pipe body;
[0107] Step S2: Determine whether the minimum radius of curvature Re of the hot-bent pipe, under the condition of meeting the stress requirements of the long-distance pipeline, is less than the maximum radius of curvature R of the hot-bent pipe manufactured in the factory. h ,Right now Figure 3 In the condition that Re < R h If Re < R h This indicates that the hot-bent pipe manufactured by the factory meets the stress requirements of long-distance pipelines, and there is no need to replace the hot-bent pipe; that is, a combined cold-bent pipe is not used to replace the hot-bent pipe. If Re ≥ R h Then proceed to step S3.
[0108] Step S3: Calculate the first maximum distance B that deviates from the preset path of the hot-bent pipe arc that meets the stress requirements of the long-distance pipeline.
[0109] Step S4: Based on the first maximum distance B calculated in Step S3 for the deviation between the hot-bent pipe arc direction and the preset path to meet the stress requirements of the long-distance pipeline, determine whether the actual arc direction of the hot-bent pipe is less than the second maximum distance W for the deviation between the arc direction of the hot-bent pipe and the preset path under the condition of meeting the stress requirements of the long-distance pipeline. If yes, proceed to Step S5; otherwise, proceed to Step S1, that is, change the pipeline parameters of the hot-bent pipe and continue to execute the remaining steps.
[0110] Step S5: Calculate the pipe parameters required for the cold-bent pipes under the conditions of Step S3. This may include the number of cold-bent pipes required for the long-distance pipeline and the angle β of a single cold-bent pipe. cand the radius of curvature R of a single cold-bent bend. cu .
[0111] Step S6: Compare the angle of a single cold-bent pipe with the maximum angle that can be used to make a cold-bent pipe, and determine the angle β of a single cold-bent pipe. c Less than the maximum angle β that can be used to make cold-bent pipes M , i.e. β c <β M And the radius of curvature R of the cold-bent pipe cu Greater than the radius of curvature R that can be used to make cold-bent pipes c R cu >R c In this case, the pipeline parameters (number of cold-bent bends, radius of curvature, and angle, etc.) of the combined cold-bent bends can be obtained based on the minimum length of the main pipe for making a single cold-bent bend and the arc length of the bend that meets the stress requirements of the long-distance pipeline.
[0112] The method provided by the embodiments of the present invention will be further described below through optional examples.
[0113] Please refer to the examples. Figures 4-7 .
[0114] 1) For a certain long-distance pipeline project, the outer diameter D of the hot-bent pipe is 323.8mm. After consulting with the supplier of hot-bent pipe, it was learned that the maximum curvature radius that can be produced is 12D, that is, 12×323.8mm.
[0115] 2) Based on research, the minimum length L of the main pipe for manufacturing a single cold-bent pipe is determined. s =11.5m, the maximum angle β for cold-bent pipe construction. M =27°, minimum radius of curvature R c =40D, the minimum length of the straight pipe section on both sides of the cold-bent bend is a = 0.5m.
[0116] 3) After performing stress analysis on a certain pipe section in this project, it was found that... Figure 4 The stresses at two locations, marked IP0403 and IP0404, exceeded the standard requirements, with hot-bending angles α of 65° and 90° respectively. After adjusting the radius of curvature of the hot-bent pipe, the minimum radius of curvature R required to meet the stress requirements was calculated. e These are 100D and 40D respectively; please refer to the detailed illustrations. Figure 5 .
[0117] 4) By comparison, the maximum radius of curvature R of the hot-bent pipe manufactured in the factory is... h =12D is less than the minimum radius of curvature R of the hot-bent pipe that meets the stress requirements. e(IP0403) =100D and R e(IP0404)=40D. This means that the factory cannot manufacture hot-bent pipes that meet the stress requirements, and multiple cold-bent pipes need to be combined to form a long-distance pipeline in order to reduce the stress in the long-distance pipeline.
[0118] 5) According to the formula:
[0119] L pr =πR e α / 180
[0120] b = R e (1 / cos(0.5α)-1)
[0121] The arc length L of the hot-bent pipe that meets the stress requirements was calculated. pr(IP0403) =36.7m and the maximum distance b that the arc deviates from the preset path (IP0403) =6m; Arc length L of hot-bent pipe to meet stress requirements pr(IP0404) =20.3m and the maximum distance b that the arc deviates from the preset path (IP0403) =5.4m.
[0122] 6) Determine whether the actual arc direction of the hot-bent pipe meets the design requirements of the preset pipeline path, see... Figure 6 and Figure 7 ,in Figure 6 and Figure 7 The land acquisition area in the invention can be considered as the boundary of the preset path of the present invention, that is, the preset path provided by the embodiments of the present invention cannot exceed the limit. Figure 6 and Figure 7 The scope of land acquisition in the document.
[0123] 7) According to the formula Calculate the number n of cold-bent pipes. (IP0403) =5,n (IP0404) =4; according to the formula Calculate the angle β of a single cold-bent pipe c(IP0403) =13°, β c(IP0404) =22.5°; according to the formula Calculate the actual radius of curvature R of cold-bent pipe cu(IP0403) =143D,R cu(IO0404) =83D.
[0124] 8) Compare the pipe parameters of the cold-bent pipe in step 7) and step 2) to see if they meet the following formula requirements respectively:
[0125] β c <β M
[0126] R cu >R c
[0127] The results are shown below: βc(IP0403) =13°<β M =27°R cu(IP0403) =143D>R c =40D;
[0128] β c(IP0404) =22.5°<β M =27°R cu(IP0404) =83D>R c =40D
[0129] That is, the pipe parameters of the cold-bent pipe meet the above requirements.
[0130] 9) Based on the above steps, determine the pipe parameters of the combined cold bending pipe that can be used to replace the hot bending pipe for construction and installation.
[0131] The pipe parameters for using combined cold-bent bends and the locations where hot-bent bends can be replaced are shown in Table 1:
[0132] Table 1. Detailed list of cold-bent pipe combinations that can replace hot-bent pipes.
[0133]
[0134] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method for reducing stress in long-distance pipelines, characterized in that, The method includes: Step 101: Obtain the maximum radius of curvature for hot-bent pipes manufactured in the factory; Step 102: Obtain the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline; Step 103: Determine whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines; Step 104: If so, the long-distance pipeline is formed by hot bending of the pipe. Step 105: If not, then use combined cold-bent pipes to form the long-distance pipeline.
2. The method for reducing stress in long-distance pipelines according to claim 1, characterized in that, Also includes: Obtain the angle of the hot-bent pipe; Based on the angle of the hot-bent pipe and the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline, it is determined whether the actual arc direction of the hot-bent pipe meets the preset path direction. If yes, proceed to step 103; otherwise, adjust the angle of the hot-bent tube until the actual arc of the hot-bent tube meets the preset path direction, then proceed to step 103.
3. The method for reducing stress in long-distance pipelines according to claim 2, characterized in that, The step of determining whether the actual arc direction of the hot-bent pipe meets the preset path direction includes: Obtain the first maximum distance B, whereby the arc direction of the hot-bent pipe deviates from the preset path under the condition that the stress requirements of the long-distance pipeline are met; Obtain the second maximum distance W from the actual arc direction of the hot-bent pipe to the preset path; Determine whether the second maximum distance W is greater than the first maximum distance B; If not, adjust the angle of the hot-bent tube until the actual arc of the hot-bent tube meets the preset path. If yes, determine that the actual arc of the hot-bent tube meets the preset path.
4. The method for reducing stress in long-distance pipelines according to claim 3, characterized in that, The first maximum distance that the arc of the hot-bent pipe deviates from the preset path can be obtained by the following formula: B=R e (1 / cos(0.5α)-1) Among them, R e The minimum radius of curvature of the hot-bent pipe is defined as the minimum radius of curvature required to meet the stress requirements of the long-distance pipeline. α is the angle of the hot-bent pipe, and B is the first maximum distance by which the arc of the hot-bent pipe deviates from the preset path.
5. The method for reducing stress in long-distance pipelines according to claim 1, characterized in that, Step 105 includes: Obtain the number of cold-bent bends, the angle of each cold-bent bend, and the radius of curvature of each cold-bent bend; The required combination of cold-bent bends to form the long-distance pipeline is determined based on the number of cold-bent bends, the angle of each cold-bent bend, and the radius of curvature of each cold-bent bend.
6. The method for reducing stress in long-distance pipelines according to claim 5, characterized in that, Obtain the quantity of cold-bent pipes, including: Obtain the arc length of the hot-bent pipe under the minimum radius of curvature required to meet the stress requirements of the long-distance pipeline, and obtain the minimum length of the main pipe for making a single cold-bent pipe. The number of cold-bent pipes is determined based on the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines, the arc length of the hot-bent pipe, and the minimum length of the main pipe for making a single cold-bent pipe.
7. The method for reducing stress in long-distance pipelines according to claim 6, characterized in that, The number of cold-bent pipes can be obtained using the following formula: Where n is the number of cold-bent pipes, L pr To determine the arc length of a hot-bent bend under the minimum radius of curvature required to meet the stress requirements of long-distance pipelines, L s Minimum length of the main pipe for making a single cold-bent pipe.
8. The method for reducing stress in long-distance pipelines according to claim 5, characterized in that, Obtaining the angle of cold-bent pipe bending includes obtaining the angle of hot-bent pipe bending. The angle of the cold-bent tube is determined based on the angle of the hot-bent tube and the number of cold-bent tubes.
9. The method for reducing stress in long-distance pipelines according to claim 8, characterized in that, The angle of the single cold-bent pipe is obtained using the following formula: Where, β c α is the angle of a single cold-bent pipe, n is the angle of the hot-bent pipe, and n is the number of cold-bent pipes.
10. The method for reducing stress in long-distance pipelines according to claim 6, characterized in that, To obtain the radius of curvature of a single cold-bent pipe, including: Obtain the minimum length of the main pipe for a single cold-bent bend during construction; The radius of curvature of the cold-bent pipe is obtained based on the angle of the single cold-bent pipe, the minimum length of the main pipe for making the single cold-bent pipe, and the minimum length of the straight pipe sections on both sides of the cold-bent pipe body.
11. The method for reducing stress in long-distance pipelines according to claim 10, characterized in that, The radius of curvature of the single cold-bent pipe is obtained by the following formula: Among them, R cu Let β be the radius of curvature of a single cold-bent pipe. c For the angle of a single cold-bent pipe, L s denoted as the minimum length of the main pipe of a single cold-bent bend, and 'a' as the minimum length of the straight pipe sections on both sides of the cold-bent bend body.
12. The method for reducing stress in long-distance pipelines according to claim 5, characterized in that, Based on the number of cold-bent bends, the angle of each individual cold-bent bend, and the radius of curvature of each individual cold-bent bend, the required combination of cold-bent bends to form the long-distance pipeline is determined, including: Determine the angle of a single cold-bent pipe and the maximum angle that can be used to make cold-bent pipes; determine the radius of curvature of a single cold-bent pipe and the minimum radius of curvature that can be used to make cold-bent pipes. If the angle of a single cold-bent pipe is less than the maximum angle that can be used to make a cold-bent pipe, and the radius of curvature of a single cold-bent pipe is greater than the minimum radius of curvature that can be used to make a cold-bent pipe, then the number, angle, and radius of curvature of the combined cold-bent pipes that need to be combined to form the long-distance pipeline are determined based on the number of cold-bent pipes, the angle of a single cold-bent pipe, and the radius of curvature of a single cold-bent pipe.
13. A system for reducing stress in long-distance pipelines, characterized in that, It includes a processor and a memory, the memory storing a computer program, which, when executed by the processor, performs the following process: Step 101: Obtain the maximum radius of curvature for hot-bent pipes manufactured in the factory; Step 102: Obtain the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of the long-distance pipeline; Step 103: Determine whether the maximum radius of curvature of the hot-bent pipe manufactured in the factory is greater than the minimum radius of curvature of the hot-bent pipe under the condition of meeting the stress requirements of long-distance pipelines; Step 104: If so, the long-distance pipeline is formed by hot bending of the pipe. Step 105: If not, then use combined cold-bent pipes to form the long-distance pipeline.