Welding method and welding device for long-distance pipeline, processor and storage medium

Abstract

The embodiment of the present invention provides a welding method and welding device, processor and storage medium for long-distance pipelines, which belongs to the technical field of pipeline welding. The welding method for long-distance pipelines includes: obtaining a preset delivery volume of the long-distance pipeline; determining the outer diameter of the long-distance pipeline according to the preset delivery volume; determining the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the outer diameter of the pipeline and the preset delivery volume, wherein the curved pipe wall thickness is greater than the straight pipe wall thickness; determining the straight pipe inner diameter of the straight pipe and the curved pipe inner diameter of the curved pipe according to the outer diameter and the straight pipe wall thickness of the pipeline, the outer diameter and the curved pipe wall thickness of the pipeline, respectively; correcting the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, wherein the corrected inner diameter of the straight pipe is equal to the inner diameter of the curved pipe; selecting the straight pipe and the curved pipe according to the corrected inner diameter and the straight pipe wall thickness of the straight pipe, the inner diameter and the curved pipe wall thickness of the curved pipe; welding the selected straight pipe and curved pipe. The technical solution of the embodiment of the present invention can reduce the hidden dangers of weld failure.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline welding, and in particular to a welding method and welding device, a processor and a storage medium for long-distance pipelines. Background Art

[0002] In the prior art, when straight pipes and curved pipes in long-distance pipelines are butt-welded, the root weld often forms a misaligned edge inside the pipeline. The existence of the misaligned edge easily causes stress concentration in the weld, that is, uneven stress distribution, which may lead to the hidden danger of weld failure during subsequent use. Therefore, the existing welding methods for long-distance pipelines have the hidden danger of weld failure. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a welding method for a long-distance pipeline, a welding device for a long-distance pipeline, a processor, a long-distance pipeline and a storage medium to solve the problem of weld failure hidden danger in the prior art.

[0004] In order to achieve the above-mentioned object, a first aspect of an embodiment of the present invention provides a welding method for a long-distance pipeline, wherein the long-distance pipeline includes a straight pipe and a curved pipe, and the welding method includes:

[0005] Obtain the preset delivery volume of long-distance pipelines;

[0006] Determine the outer diameter of the long-distance pipeline according to the preset delivery volume;

[0007] Determine the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the outer diameter of the pipeline and the preset conveying volume, wherein the curved pipe wall thickness is greater than the straight pipe wall thickness;

[0008] Determine the inner diameter of the straight pipe and the inner diameter of the bent pipe according to the outer diameter of the pipe and the wall thickness of the straight pipe, and the outer diameter of the pipe and the wall thickness of the bent pipe;

[0009] Correcting the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, wherein the corrected inner diameter of the straight pipe is equal to the inner diameter of the bent pipe;

[0010] Select straight pipes and bent pipes according to the corrected inner diameter and wall thickness of straight pipes, inner diameter and wall thickness of bent pipes;

[0011] The selected straight pipes and bent pipes are welded.

[0012] In an embodiment of the present invention, determining the outer diameter of the long-distance pipeline according to a preset delivery volume includes: determining the outer diameter of the long-distance pipeline according to the preset delivery volume based on a pre-stored correspondence between the delivery volume and the outer diameter of the pipeline.

[0013] In an embodiment of the present invention, the straight pipe wall thickness of a straight pipe and the curved pipe wall thickness of a curved pipe are determined according to the outer diameter of the pipeline and a preset delivery volume, including: obtaining the regional level of the area where the long-distance pipeline is located, wherein the regional level is obtained according to the population density; determining the straight pipe strength coefficient corresponding to the regional level according to the regional level; determining the straight pipe pressure of the straight pipe according to the preset delivery volume; determining the minimum yield strength of the straight pipe and the curvature radius of the curved pipe according to the outer diameter of the pipeline; determining the straight pipe wall thickness according to the straight pipe pressure, the outer diameter of the pipeline, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe; determining the curved pipe wall thickness according to the straight pipe wall thickness, the curvature radius and the outer diameter of the pipeline.

[0014] In the embodiment of the present invention, the preset parameters of the straight pipe include the weld coefficient of the straight pipe and the temperature reduction coefficient of the straight pipe; the wall thickness of the straight pipe is determined according to the straight pipe pressure, the outer diameter of the pipe, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe, including determining the wall thickness of the straight pipe according to formula (1):

[0015]

[0016] Among them, δ is the wall thickness of the straight pipe, P is the straight pipe pressure, D is the outer diameter of the pipe, σ S is the minimum yield strength, is the weld coefficient, F is the straight pipe strength coefficient, and t is the temperature reduction coefficient.

[0017] In an embodiment of the present invention, the wall thickness of the bent pipe is determined according to the wall thickness of the straight pipe, the radius of curvature and the outer diameter of the pipe, including determining the wall thickness of the bent pipe according to formula (2):

[0018] δ b =δ×m=δ×(4R-d / 4R-2d) Formula (2)

[0019] Among them, δ b is the wall thickness of the bent pipe, δ is the wall thickness of the straight pipe, m is the wall thickness increase coefficient of the bent pipe, R is the radius of curvature, and d is the outer diameter of the pipe.

[0020] In the embodiment of the present invention, before welding the selected straight pipe and the bent pipe, the method further includes: grinding the difference in wall thickness of the pipe outer diameter formed at the connection between the straight pipe and the bent pipe to less than 2.5 mm.

[0021] In an embodiment of the present invention, the welding method for long-distance pipelines further includes: the slope formed by the difference in outer diameter wall thickness of the pipeline after grinding is less than 15°.

[0022] In an embodiment of the present invention, the welding method for a long-distance pipeline further includes: grinding the wall thickness difference of the outer diameter of the pipeline of a preset length.

[0023] In an embodiment of the present invention, the selected straight pipe and the bent pipe are welded, including: welding the selected straight pipe and the bent pipe by root welding, filling welding and cap welding in sequence.

[0024] In the embodiment of the present invention, the single filling thickness corresponding to the filling welding does not exceed 2.5 mm.

[0025] In the embodiment of the present invention, the straight tube strength coefficient ranges from 0.4 to 0.8.

[0026] A second aspect of an embodiment of the present invention provides a processor configured to execute the above-mentioned welding method for a long-distance pipeline.

[0027] A third aspect of an embodiment of the present invention provides a welding device for a long-distance pipeline, comprising: a processor according to the above.

[0028] A fourth aspect of an embodiment of the present invention provides a long-distance pipeline, which includes a straight pipe and a curved pipe. The long-distance pipeline is welded according to the above-mentioned welding method for the long-distance pipeline.

[0029] A fifth aspect of an embodiment of the present invention provides a machine-readable storage medium, on which instructions are stored. When the instructions are executed by a processor, the processor executes the above-mentioned welding method for long-distance pipelines.

[0030] The above-mentioned welding method for long-distance pipelines obtains a preset delivery volume of the long-distance pipeline, determines the outer diameter of the long-distance pipeline according to the preset delivery volume, determines the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the outer diameter of the pipeline and the preset delivery volume, thereby determining the straight pipe inner diameter of the straight pipe and the curved pipe inner diameter of the curved pipe according to the outer diameter and the straight pipe wall thickness, and the outer diameter and the curved pipe wall thickness, respectively, and then corrects the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, and the corrected inner diameter of the straight pipe is equal to the inner diameter of the curved pipe, thereby selecting the straight pipe and the curved pipe according to the corrected inner diameter and the straight pipe wall thickness, and the inner diameter and the curved pipe wall thickness, respectively, and welding the selected straight pipe and curved pipe. The above scheme reduces the inner diameter of the straight pipe to the same inner diameter as that of the bent pipe, which can solve the problem that the existing long-distance pipelines usually use straight pipes and bent pipes with equal outer diameters and unequal wall thicknesses for butt welding, resulting in misalignment inside the pipeline, which easily causes stress concentration in the weld, greatly reducing the hidden dangers of weld failure. Moreover, since the misalignment of the butt joints with unequal wall thicknesses occurs on the weld surface of the pipeline, it is easier to take measures to deal with it than when the misalignment occurs inside the pipeline, thereby improving the stability of the pipeline welding quality and ensuring the safety of the long-distance pipeline.

[0031] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0033] Figure 1 The schematic diagram shows a flow chart of a welding method for a long-distance pipeline in one embodiment of the present invention;

[0034] FIG2( a ) schematically shows a schematic structural diagram of a straight pipe and a curved pipe in the prior art in one embodiment of the present invention;

[0035] FIG. 2( b ) schematically shows a schematic diagram of the butt welding of the straight pipe and the bent pipe in FIG. 2( a ) in one embodiment of the present invention;

[0036] FIG3( a ) schematically shows a schematic diagram of the structure of a straight pipe and a curved pipe in one embodiment of the present invention;

[0037] FIG. 3( b ) schematically shows a schematic diagram of the butt welding of the straight pipe and the bent pipe in FIG. 3( a ) in one embodiment of the present invention.

[0038] Description of Reference Numerals

[0039] 1 Straight pipe 2 Bend pipe

[0040] 3 Welding seams DETAILED DESCRIPTION

[0041] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0042] Existing long-distance pipelines usually use straight pipes and curved pipes with equal outer diameters and unequal wall thicknesses for butt welding. The root welds are misaligned when butted, which easily leads to stress concentration problems and the risk of weld failure after welding.

[0043] In order to solve the above problems, Figure 1 The schematic diagram of the process flow of the welding method for long-distance pipeline in one embodiment of the present invention is shown schematically. Figure 1 As shown, in an embodiment of the present invention, a welding method for a long-distance pipeline is provided, which may specifically include the following steps:

[0044] Step S102, obtaining a preset transport volume of the long-distance pipeline.

[0045] Step S104, determining the outer diameter of the long-distance pipeline according to the preset delivery volume.

[0046] Step S106, determining the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the outer diameter of the pipeline and the preset conveying volume, wherein the curved pipe wall thickness is greater than the straight pipe wall thickness.

[0047] Step S108, determining the inner diameter of the straight pipe and the inner diameter of the bent pipe according to the outer diameter of the pipe and the wall thickness of the straight pipe, and the outer diameter of the pipe and the wall thickness of the bent pipe.

[0048] Step S110, correcting the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, wherein the corrected inner diameter of the straight pipe is equal to the inner diameter of the bent pipe.

[0049] Step S112, selecting a straight pipe and a bent pipe respectively according to the corrected inner diameter and wall thickness of the straight pipe, inner diameter and wall thickness of the bent pipe.

[0050] Step S112, welding the selected straight pipe and bent pipe.

[0051] It can be understood that the long-distance pipeline can be used to transport natural gas, oil and other media, and the preset delivery volume is the medium delivery volume of the pre-set long-distance pipeline within a preset time range (for example, one year), such as the gas delivery volume.

[0052] Specifically, the processor can obtain the preset delivery volume of the long-distance pipeline input by the user or pre-set and stored, and determine the outer diameter of the pipeline of the long-distance pipeline according to the preset delivery volume. For example, the outer diameter of the pipeline of the long-distance pipeline can be determined according to the preset delivery volume based on the corresponding relationship between the delivery volume and the outer diameter of the pipeline, or the preset delivery volume can be used as an input based on a pre-stored algorithm that characterizes the relationship between the delivery volume and the outer diameter of the pipeline to obtain an output result, that is, the outer diameter of the pipeline of the long-distance pipeline. Further, the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe are determined according to the outer diameter of the pipeline and the preset delivery volume. For example, the straight pipe wall thickness of the straight pipe can be determined according to the corresponding relationship among the outer diameter of the pipeline, the preset delivery volume and the straight pipe wall thickness, and the curved pipe wall thickness of the curved pipe can be determined according to the corresponding relationship among the outer diameter of the pipeline, the preset delivery volume and the curved pipe wall thickness. The straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe can also be determined according to the corresponding relationship among the outer diameter of the pipeline, the preset delivery volume, the straight pipe wall thickness and the curved pipe wall thickness, wherein the curved pipe wall thickness is greater than the straight pipe wall thickness. Then, the straight pipe inner diameter of the straight pipe is determined according to the pipe outer diameter and the straight pipe wall thickness, that is, the difference between the pipe outer diameter and the straight pipe wall thickness is determined as the straight pipe inner diameter of the straight pipe. The bent pipe inner diameter of the curved pipe is determined according to the pipe outer diameter and the curved pipe wall thickness, that is, the difference between the pipe outer diameter and the curved pipe wall thickness is determined as the curved pipe inner diameter of the curved pipe. It can be known that since the curved pipe wall thickness is greater than the straight pipe wall thickness, the curved pipe inner diameter is smaller than the straight pipe inner diameter. At this time, the processor can correct the straight pipe inner diameter, that is, reduce the straight pipe inner diameter, so that the corrected straight pipe inner diameter is equal to the curved pipe inner diameter. Therefore, the processor can select the type of straight pipe according to the corrected inner diameter and wall thickness of the straight pipe, and select the type of bent pipe according to the inner diameter and wall thickness of the bent pipe. Then, the processor can control a specific actuator (such as a welding machine or a welding robot) to weld the selected straight pipe and bent pipe to obtain a long-distance pipeline. At this time, the inner diameter of the straight pipe is the same as the inner diameter of the bent pipe, the wall thickness of the straight pipe and the wall thickness of the bent pipe remain unchanged, and the outer diameter of the straight pipe is not the same as the outer diameter of the bent pipe.

[0053] The above-mentioned welding method for long-distance pipelines obtains a preset delivery volume of the long-distance pipeline, determines the outer diameter of the long-distance pipeline according to the preset delivery volume, determines the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the outer diameter of the pipeline and the preset delivery volume, thereby determining the straight pipe inner diameter of the straight pipe and the curved pipe inner diameter of the curved pipe according to the outer diameter and the straight pipe wall thickness, and the outer diameter and the curved pipe wall thickness, respectively, and then corrects the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, and the corrected inner diameter of the straight pipe is equal to the inner diameter of the curved pipe, thereby selecting the straight pipe and the curved pipe according to the corrected inner diameter and the straight pipe wall thickness, and the inner diameter and the curved pipe wall thickness, respectively, and welding the selected straight pipe and curved pipe. The above scheme reduces the inner diameter of the straight pipe to the same inner diameter as that of the bent pipe, which can solve the problem that the existing long-distance pipelines usually use straight pipes and bent pipes with equal outer diameters and unequal wall thicknesses for butt welding, resulting in misalignment inside the pipeline, which easily causes stress concentration in the weld, greatly reducing the hidden dangers of weld failure. Moreover, since the misalignment of the butt joints with unequal wall thicknesses occurs on the weld surface of the pipeline, it is easier to take measures to deal with it than when the misalignment occurs inside the pipeline, thereby improving the stability of the pipeline welding quality and ensuring the safety of the long-distance pipeline.

[0054] In one embodiment, determining the outer diameter of the long-distance pipeline according to a preset delivery volume includes: determining the outer diameter of the long-distance pipeline according to the preset delivery volume based on a pre-stored correspondence between the delivery volume and the outer diameter of the pipeline.

[0055] It can be understood that the processor can pre-store the corresponding relationship between the pipeline delivery volume and the pipeline outer diameter, so as to determine the pipeline outer diameter of the long-distance pipeline according to the preset delivery volume.

[0056] In one embodiment, the straight pipe wall thickness of a straight pipe and the curved pipe wall thickness of a curved pipe are determined according to the outer diameter of the pipeline and a preset delivery volume, including: obtaining the regional level of the area where the long-distance pipeline is located, wherein the regional level is obtained according to the population density; determining the straight pipe strength coefficient corresponding to the regional level according to the regional level; determining the straight pipe pressure of the straight pipe according to the preset delivery volume; determining the minimum yield strength of the straight pipe and the curvature radius of the curved pipe according to the outer diameter of the pipeline; determining the straight pipe wall thickness according to the straight pipe pressure, the outer diameter of the pipeline, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe; determining the curved pipe wall thickness according to the straight pipe wall thickness, the curvature radius and the outer diameter of the pipeline.

[0057] It can be understood that a plurality of different regional levels can be obtained according to the size of population density, and the straight pipe strength coefficient is the strength coefficient of the straight pipe, which is related to the regional level. The preset parameters of the straight pipe are the parameters of the straight pipe set in advance, such as the temperature reduction coefficient of the straight pipe.

[0058] Specifically, the processor can obtain the regional level of the region where the long-distance pipeline is located, which is input by the user, so as to determine the straight pipe strength coefficient corresponding to the regional level according to the regional level, and determine the straight pipe pressure of the straight pipe according to the preset delivery volume. For example, according to the algorithm pre-stored to characterize the relationship between the regional level and the straight pipe strength coefficient, the regional level can be used as an input to obtain the output result, i.e., the straight pipe strength coefficient. According to the algorithm pre-stored to characterize the relationship between the delivery volume and the pressure, the preset delivery volume can be used as an input to obtain the output result, i.e., the straight pipe pressure of the straight pipe. Then, the processor can determine the minimum yield strength of the straight pipe and the curvature radius of the bend according to the outer diameter of the pipeline. For example, according to the corresponding relationship between the outer diameter of the pipeline and the steel grade, the steel grade corresponding to the outer diameter of the pipeline can be determined, and then the minimum yield strength of the straight pipe can be determined according to the steel grade, or, based on the algorithm pre-stored to characterize the outer diameter of the pipeline and the curvature radius, the curvature radius of the bend can be determined according to the outer diameter of the pipeline. Thus, the wall thickness of the straight pipe is determined according to the straight pipe pressure, the outer diameter of the pipe, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe. For example, the wall thickness of the straight pipe can be determined by a pre-trained algorithm, which may include parameters such as the straight pipe pressure, the outer diameter of the pipe, the minimum yield strength, the straight pipe strength coefficient, the preset parameters of the straight pipe and the straight pipe wall thickness. Then, the wall thickness of the bent pipe is determined according to the straight pipe wall thickness, the radius of curvature and the outer diameter of the pipe. For example, the wall thickness of the bent pipe can be determined by a pre-determined algorithm including the straight pipe wall thickness, the radius of curvature, the outer diameter of the pipe and the wall thickness of the bent pipe.

[0059] In one embodiment, the preset parameters of the straight pipe include the weld coefficient of the straight pipe and the temperature reduction coefficient of the straight pipe; the wall thickness of the straight pipe is determined according to the straight pipe pressure, the outer diameter of the pipe, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe, including determining the wall thickness of the straight pipe according to formula (1):

[0060]

[0061] Among them, δ is the wall thickness of the straight pipe, P is the straight pipe pressure, D is the outer diameter of the pipe, σ S is the minimum yield strength, is the weld coefficient, F is the straight pipe strength coefficient, and t is the temperature reduction coefficient.

[0062] In the embodiment of the present invention, the above formula (1) takes into account multiple parameters of the straight pipe. By determining the wall thickness of the straight pipe using the above formula (1), the accuracy of the wall thickness of the straight pipe can be improved.

[0063] In one embodiment, the wall thickness of the bent pipe is determined according to the wall thickness of the straight pipe, the radius of curvature, and the outer diameter of the pipe, including determining the wall thickness of the bent pipe according to formula (2):

[0064] δ b =δ×m=δ×(4R-d / 4R-2d) Formula (2)

[0065] Among them, δb is the wall thickness of the bent pipe, δ is the wall thickness of the straight pipe, m is the wall thickness increase coefficient of the bent pipe, R is the radius of curvature, and d is the outer diameter of the pipe.

[0066] In the embodiment of the present invention, the wall thickness of the bent pipe is determined by the above formula (2), so that the accuracy of the wall thickness of the bent pipe can be improved.

[0067] In one embodiment, before welding the selected straight pipe and the bent pipe, the method further includes: grinding the difference in wall thickness of the pipe outer diameter formed at the connection between the straight pipe and the bent pipe to less than 2.5 mm.

[0068] It can be understood that since the thickness of each weld during the welding process is 2.5mm, before welding the selected straight pipe and the bent pipe, the difference in pipe outer diameter wall thickness formed at the connection between the straight pipe and the bent pipe can be polished to less than 2.5mm, so that each layer of welding can cover the misalignment formed at the connection to facilitate welding. If the pipe outer diameter wall thickness difference is less than 2.5mm, grinding is not required. If the pipe outer diameter wall thickness is greater than or equal to less than 2.5mm, the pipe outer diameter wall thickness difference formed at the connection between the straight pipe and the bent pipe can be polished and smoothed until the pipe outer diameter wall thickness difference is less than 2.5mm.

[0069] In one embodiment, the welding method for long-distance pipelines further includes: the slope formed by the difference in outer diameter wall thickness of the pipeline after grinding is less than 15°.

[0070] It can be understood that grinding the pipe outer diameter wall thickness difference formed at the connection between the straight pipe and the bent pipe to a slope less than 15° can achieve better welding results.

[0071] In one embodiment, the welding method for long-distance pipelines further includes: grinding the wall thickness difference of the outer diameter of the pipeline of a preset length.

[0072] It can be understood that the preset length is a preset grinding length, such as 45 mm. By grinding the preset length of the pipeline outer diameter wall thickness difference, costs can be reduced and grinding of the entire length of the long-distance pipeline can be avoided.

[0073] In one embodiment, the grinding and smoothing process includes grinding the outer diameter wall thickness difference of the long-distance pipeline to less than 0.5δ and grinding to form a slope less than 15°, wherein δ is at least one of the straight pipe wall thickness and the curved pipe wall thickness.

[0074] In one embodiment, welding the selected straight pipe and the bent pipe includes: welding the selected straight pipe and the bent pipe in sequence by means of root welding, filling welding and cap welding.

[0075] It can be understood that the welding process of the bent pipe and the straight pipe may include root welding, filling welding and cap welding, and the root welding, filling welding and cap welding are performed in sequence.

[0076] In one embodiment, the single filling thickness corresponding to the filling weld does not exceed 2.5 mm.

[0077] It is understood that the single filling thickness during filling welding does not exceed 2.5mm. Root welding (including hot welding) completes the welding of the blunt edge, and then filling welding is performed, and the thickness of each filling does not exceed 2.5mm, and finally cap welding is performed.

[0078] In one embodiment, the straight tube strength coefficient ranges from 0.4 to 0.8.

[0079] It can be understood that the straight pipe strength coefficient in this range can improve the transportation safety of long-distance pipelines.

[0080] It can be understood that the range of the straight pipe strength coefficient may include 0.4 to 0.8, and the regional level may include Class I, Class II, Class II, Class III or Class IV according to population density. Among them, the design coefficient of Class I area may be 0.8, the design coefficient of Class I area may be 0.72, the design coefficient of Class II area may be 0.6, the design coefficient of Class III area may be 0.5, and the design coefficient of Class IV area may be 0.4.

[0081] In one embodiment, the long-distance pipeline may be the entire mountain long-distance pipeline or a local area of ​​the mountain long-distance pipeline, and the length is usually not more than 50 km. The welding method for the long-distance pipeline can be applied to mountainous areas with complex terrain (generally the slope is usually above 15°), 3 to 5 ditches / km, and 3 to 5 rural roads / km.

[0082] In an embodiment of the present invention, the welding method for long-distance pipelines can be used for pipeline welding construction in mountainous areas with large terrain undulations, more than 60% of the area with a slope of more than 15°, and complex construction conditions (for example, 3 to 5 ditches / km, 3 to 5 rural roads / km).

[0083] In the prior art, as shown in FIG. 2(a) and FIG. 2(b), the straight pipe and the curved pipe have the same outer diameter and different wall thickness. In an embodiment of the present invention, as shown in FIG. 3(a) and FIG. 3(b), the straight pipe and the curved pipe have different wall thicknesses but the same inner diameter. The wall thickness of the straight pipe (e.g., straight steel pipe) and the curved pipe (e.g., hot-bent curved pipe) constituting the long-distance pipeline can be determined first. As shown in FIG. 2(a) and FIG. 2(b), under the same design coefficient (i.e., the straight pipe strength coefficient), the wall thickness of the curved pipe 2 is greater than the wall thickness of the straight pipe 1 and the inner diameter of the curved pipe 2 is smaller than the inner diameter of the straight pipe 1, so that the weld 3 formed after the curved pipe 2 and the straight pipe 1 are welded is staggered on the inner wall of the pipeline, resulting in stress concentration and other problems. As shown in FIG. 3(a) and FIG. 3(b), the inner diameter of the straight pipe 1 is reduced to the same as that of the curved pipe 2, and the wall thickness remains unchanged. The bent pipe 2 and the straight pipe 1 are welded, and the misalignment of the weld 3 after welding is outside the pipe. The misalignment surface formed by welding can be polished and smoothed (when the difference in the outer diameter wall thickness of the pipe at the misalignment is greater than or equal to 2.5 mm) to reduce the probability of weld failure.

[0084] In an exemplary embodiment of the present invention, the welding method can achieve a one-time pass rate of more than 95%, and the misalignment rate can be within 2 mm.

[0085] The principle of equal inner diameter design for long-distance pipelines is to adjust the inner diameter of the steel pipe through the whole pipe internal diameter expansion process, so as to meet the requirements of equal inner diameter design of steel pipes. If the inner diameter is the same but the wall thickness is different, the outer diameter of the pipeline will be inconsistent, and the sum of the inner diameter and the wall thickness is the outer diameter of the pipeline. Taking a long-distance pipeline project as an example, according to the relevant provisions of GB50251 (Design Code for Gas Pipeline Engineering), the regional grade of the area where the long-distance pipeline is located is determined to be level 2, and the corresponding design coefficient (i.e., straight pipe strength coefficient) is 0.6. The wall thickness of the pipe for the general section of the line is 17.5mm, and the outer diameter is D1016mm; the wall thickness of the pipe for hot simmering is 19.2mm, and the outer diameter is D1017.7mm.

[0086] The welding method for a long-distance pipeline provided by an embodiment of the present invention is described below in conjunction with another specific embodiment.

[0087] Taking a long-distance pipeline project as an example, the design delivery pressure of the project is 10.0MPa, the design outer diameter of the straight pipe section is 1016mm, and the design outer diameter of the hot-bent pipe section is 1017.7mm. According to the design principles of long-distance pipelines, the corresponding straight pipe strength coefficient is determined to be 0.6 when the regional grade is level 2, and the wall thickness and inner diameter of the straight steel pipe section and the hot-bent pipe section of the project are calculated respectively. It can be understood that the design principles of long-distance pipelines are pre-set design principles of long-distance pipelines, and the design principles of long-distance pipelines can be corresponding national standards, specifically, for example, the Code for Design of Gas Pipeline Engineering (GB 50251-2015), etc.

[0088] Among them, the wall thickness of the straight steel pipe is related to the design pressure, the outer diameter of the straight steel pipe, the strength grade of the straight steel pipe, the strength design coefficient and the temperature reduction coefficient. The wall thickness of the straight steel pipe can be calculated by formula (1), which is:

[0089]

[0090] Where, δ is the calculated wall thickness of the straight steel pipe, mm; P is the design pressure, which can be 10.0MPa; D is the outer diameter of the straight steel pipe, which can be 1016mm; σ S is the minimum yield strength of the straight steel pipe, which can be taken as 485MPa; is the straight steel pipe weld coefficient, which can be selected as 1.0; F is the strength design coefficient (i.e. the straight pipe strength coefficient), which can be selected as 0.6; t is the temperature reduction coefficient, which can be selected as 1.0. According to formula (1), the calculated wall thickness δ of the straight steel pipe is 17.46 mm, which is rounded to 17.5 mm, and the inner diameter is 981 mm.

[0091] Among them, the inner diameter of the straight steel pipe can be determined according to the difference between the outer diameter D of the straight steel pipe and the calculated wall thickness δ of the straight steel pipe.

[0092] Among them, the wall thickness of the hot-bent pipe is calculated by formula 2, which is:

[0093] δ b =δ×m=δ×(4R-d / 4R-2d) Formula (2)

[0094] In the formula, δ b is the calculated wall thickness of the hot-bent pipe, mm; δ is the calculated wall thickness of the straight steel pipe section connected by the hot-bent pipe, which can be 1016mm; m is the wall thickness increase coefficient of the hot-bent pipe; R is the curvature radius of the hot-bent pipe, which can be 6D, D is the outer diameter of the straight steel pipe; d is the outer diameter of the hot-bent pipe, which can be 1016mm. The wall thickness of the hot-bent pipe is 19.18mm, rounded to 19.2mm, and the inner diameter is 979.3mm.

[0095] Among them, the inner diameter of the hot-bent pipe can be calculated based on the outer diameter d of the hot-bent pipe and the wall thickness δ of the hot-bent pipe. b The difference is determined.

[0096] In order to avoid misalignment at the root of the weld between the straight steel pipe section and the hot-bent pipe section due to unequal inner diameters, the inner diameter of the straight steel pipe section is reduced from 981mm to 979.3mm. This can avoid the problem of misalignment inside the pipe after welding.

[0097] The equal inner diameter design principle can avoid the misalignment problem of the root weld of the unequal wall thickness butt weld in long-distance pipelines. According to statistics, compared with the original equal outer diameter and unequal wall thickness, the welding construction can reduce about 400 hot simmers or 800 misalignment problems of the root weld of the unequal wall thickness butt weld, avoiding the misalignment and stress concentration problems of the unequal wall thickness butt weld, greatly ensuring the inherent safety of the pipeline. Under the equal inner diameter design principle, the misalignment of the unequal wall thickness butt weld occurs on the weld surface, and it is easy to take measures to smooth and grind it, which can greatly eliminate the hidden dangers of weld failure.

[0098] An embodiment of the present invention provides a processor configured to execute the welding method for a long-distance pipeline according to the above embodiment.

[0099] An embodiment of the present invention provides a welding device for a long-distance pipeline, comprising: a processor according to the above embodiment.

[0100] An embodiment of the present invention provides a long-distance pipeline, which includes a straight pipe and a curved pipe. The long-distance pipeline is welded according to the welding method for the long-distance pipeline in the above embodiment.

[0101] An embodiment of the present invention provides a machine-readable storage medium, on which instructions are stored. When the instructions are executed by a processor, the processor executes the welding method for a long-distance pipeline according to the above-mentioned embodiment.

[0102] In summary, the beneficial effects of the embodiments of the present invention may include:

[0103] (1) The equal inner diameter design principle mentioned in the welding method for long-distance pipelines provided in the embodiment of the present invention can avoid problems such as misalignment and stress concentration at the weld root of unequal wall thickness welds in long-distance pipelines, resulting in unstable pipeline welding quality and reducing the hidden danger of weld failure.

[0104] (2) The technical solution of the embodiment of the present invention can reduce about 400 hot simmers, or 800 root weld misalignment problems of unequal wall thickness butt welds, avoid the misalignment and stress concentration problems of unequal wall thickness butt welds, and greatly ensure the inherent safety of the pipeline. Under the principle of equal inner diameter design, the misalignment of unequal wall thickness butt welds occurs on the weld surface, and it is easy to take measures to smooth and grind it, which can greatly eliminate the hidden danger of weld failure.

[0105] Although the present invention has been described above by combining with exemplary embodiments, it will be apparent to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined in the claims.

Claims

1. A welding method for long-distance pipelines, characterized in that: The long-distance pipeline includes a straight pipe and a curved pipe, and the welding method includes: Obtain the preset delivery volume of long-distance pipelines; Determining the outer diameter of the long-distance pipeline according to the preset delivery volume; Determine the straight pipe wall thickness of the straight pipe and the bent pipe wall thickness of the bent pipe according to the outer diameter of the pipeline and the preset conveying volume, wherein the bent pipe wall thickness is greater than the straight pipe wall thickness; Determine the inner diameter of the straight pipe and the inner diameter of the bent pipe according to the outer diameter of the pipe and the wall thickness of the straight pipe, and the outer diameter of the pipe and the wall thickness of the bent pipe respectively; Correcting the inner diameter of the straight pipe to obtain a corrected inner diameter of the straight pipe, wherein the corrected inner diameter of the straight pipe is equal to the inner diameter of the bent pipe; Select the straight pipe and the bent pipe respectively according to the corrected inner diameter of the straight pipe and the wall thickness of the straight pipe, the inner diameter of the bent pipe and the wall thickness of the bent pipe; Welding the selected straight pipe and the bent pipe; Wherein, determining the outer diameter of the long-distance pipeline according to the preset delivery volume comprises: determining the outer diameter of the long-distance pipeline according to the preset delivery volume based on a pre-stored correspondence between the delivery volume and the outer diameter of the pipeline; The step of determining the straight pipe wall thickness of the straight pipe and the curved pipe wall thickness of the curved pipe according to the pipeline outer diameter and the preset delivery volume comprises: Obtaining a regional level of the region where the long-distance pipeline is located, wherein the regional level is obtained based on population density; According to a pre-stored algorithm representing the relationship between the regional level and the straight pipe strength coefficient, the straight pipe strength coefficient corresponding to the regional level is determined according to the regional level; According to a pre-stored algorithm characterizing the relationship between the delivery volume and the pressure, the straight pipe pressure of the straight pipe is determined according to the preset delivery volume; Determine the minimum yield strength of the straight pipe and the curvature radius of the curved pipe according to the outer diameter of the pipe, wherein the minimum yield strength is determined according to the pre-stored correspondence between the outer diameter of the pipe and the steel grade, and the correspondence between the steel grade and the minimum yield strength, and the curvature radius is determined according to the pre-stored algorithm of the outer diameter of the pipe and the curvature radius; Determining the straight pipe wall thickness according to the straight pipe pressure, the pipe outer diameter, the minimum yield strength, the straight pipe strength coefficient and preset parameters of the straight pipe; Determining the wall thickness of the curved pipe according to the wall thickness of the straight pipe, the radius of curvature and the outer diameter of the pipe; The preset parameters of the straight pipe include the weld coefficient of the straight pipe and the temperature reduction coefficient of the straight pipe; the straight pipe wall thickness is determined according to the straight pipe pressure, the pipe outer diameter, the minimum yield strength, the straight pipe strength coefficient and the preset parameters of the straight pipe, including determining the straight pipe wall thickness according to formula (1): Wherein, δ is the wall thickness of the straight pipe, P is the straight pipe pressure, D is the outer diameter of the pipe, σ S is the minimum yield strength, is the weld coefficient, F is the straight pipe strength coefficient, and t is the temperature reduction coefficient; Determining the wall thickness of the curved pipe according to the wall thickness of the straight pipe, the radius of curvature and the outer diameter of the pipe includes determining the wall thickness of the curved pipe according to formula (2): δ b =δ×m=δ×(4R-d / 4R-2d) Formula (2) Among them, δ b is the wall thickness of the bent pipe, δ is the wall thickness of the straight pipe, m is the wall thickness increase coefficient of the bent pipe, R is the radius of curvature, and d is the outer diameter of the pipe.

2. The welding method according to claim 1, characterized in that: Before welding the selected straight pipe and the bent pipe, the following steps are further included: The difference in outer diameter wall thickness of the pipe formed at the connection between the straight pipe and the curved pipe is polished to less than 2.5 mm.

3. The welding method according to claim 2, characterized in that: Also includes: The slope formed by the difference in wall thickness of the outer diameter of the pipeline after grinding is less than 15°.

4. The welding method according to claim 2, characterized in that: Also includes: The outer diameter wall thickness difference of the pipeline of a preset length is ground.

5. The welding method according to claim 1, characterized in that: The step of welding the selected straight pipe and the bent pipe comprises: The selected straight pipe and the bent pipe are welded in sequence by means of root welding, filling welding and cap welding.

6. The welding method according to claim 5, characterized in that: The single filling thickness corresponding to the filling welding does not exceed 2.5 mm.

7. The welding method according to claim 1, characterized in that: The straight tube strength coefficient ranges from 0.4 to 0.

8.

8. A processor, characterized in that: The device is configured to perform the welding method for a long-distance pipeline according to any one of claims 1 to 7.

9. A welding device for long-distance pipelines, characterized in that: include: A processor according to claim 8.

10. A machine-readable storage medium having instructions stored thereon, characterized in that: When the instruction is executed by a processor, the processor executes the welding method for a long-distance pipeline according to any one of claims 1 to 7.

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