Selection method, system and equipment of mountain natural gas pipeline welding mode and medium

Abstract

The invention relates to the technical field of natural gas conveying, and discloses a mountain natural gas pipeline welding mode selection method, system and equipment and a medium. According to the topographic condition, the gradient information and the length information, a preliminary welding mode suitable for welding the mountain pipeline at the construction section is obtained; selecting a recommendation method of the construction section from the preliminary welding modes according to the topographic condition and the gradient information; and the recommendation method is optimized according to the gradient information and the length information of the construction section, and the final welding mode of the construction section is determined. According to the method, the influence of factors such as economy, terrains and pipes on welding method selection is fully considered, a more suitable mountain natural gas pipeline welding method can be selected through decision, and technical support is provided for mountain natural gas pipeline conveying.

Description

Technical Field

[0001] This invention relates to the field of natural gas transmission technology, specifically to a method, system, equipment, and medium for selecting welding methods for natural gas pipelines in mountainous areas. Background Technology

[0002] my country's terrain is predominantly mountainous, and a large number of pipelines must pass through mountainous areas. However, the complex geological structure and limited welding space in mountainous areas significantly impact welding quality. Furthermore, the undulating terrain, numerous bends and turns in pipelines, and restrictions on the use of large equipment further limit welding efficiency compared to construction in plains areas, posing a challenge to the selection of on-site welding methods. Therefore, it is essential to propose a method for selecting welding methods for natural gas pipelines in mountainous areas based on techno-economic evaluation.

[0003] Currently, scholars have conducted extensive research on welding construction technology and quality control for long-distance pipelines in mountainous areas. However, most of these studies focus on the difficulties of automatic welding construction in mountainous and water-rich regions, pointing out the research direction of fully automatic welding technology for mountain pipelines. They haven't given much consideration to economic factors in welding construction technology. With the increasing mileage of natural gas long-distance pipelines in my country, higher demands are being placed on welding construction technology. In addition to considering the difficulties of automatic welding construction, it is also necessary to consider economic factors simultaneously to reduce the cost of welding construction technology, which is an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a method for selecting welding methods for natural gas pipelines in mountainous areas. It fully considers the influence of factors such as economy, terrain and pipe material on the selection of welding methods, and can make decisions to select more suitable welding methods for natural gas pipelines in mountainous areas.

[0005] This invention is achieved through the following technical solution:

[0006] A method for selecting welding methods for natural gas pipelines in mountainous areas includes:

[0007] Obtain the terrain conditions, slope information, and length information of the construction section, and based on the terrain conditions, slope information, and length information, obtain the preliminary welding method suitable for welding mountain pipelines in this construction section;

[0008] Based on the terrain conditions and slope information, select the recommended method for this construction section from the preliminary welding methods;

[0009] The recommended method is optimized based on the slope and length information of the construction section to determine the final welding method for the construction section.

[0010] In some embodiments, the preliminary welding method includes fully automatic welding, combined automatic welding, single-torch automatic welding, and prefabricated automatic welding, and the fully automatic welding, combined automatic welding, single-torch automatic welding, and prefabricated automatic welding are respectively denoted as i1, i2, i3, and i4.

[0011] In some embodiments, the recommended method is selected based on the following constraints:

[0012] When the slope information indicates a terrain slope of less than 15°, the recommended methods include i1, i2, and i3;

[0013] When the slope information is a terrain slope greater than or equal to 15°, and the terrain is a short steep slope section or a river pipe jacking tunnel, the recommended methods include i2, i3 and i4;

[0014] When the terrain is a long ridge or a transverse slope, the recommended methods include i1 and i3;

[0015] When the terrain involves large-scale river excavation and road crossings, the recommended methods include i1, i2, and i3;

[0016] When the terrain is a mountain tunnel, the recommended methods include i1 and i4.

[0017] In some embodiments, the specific process of optimizing the recommendation method based on the slope information and length information of the construction section is as follows:

[0018] S1. Iterate through the slope and length information of the construction section and determine whether the slope of each section of the construction section is less than 15°. If so, jump to S2; otherwise, jump to S3.

[0019] S2. Based on cost constraints, select the preferred welding method from the preliminary welding methods according to the welding cost curve as the final welding method;

[0020] S3. For a construction segment group consisting of multiple consecutive construction segments with a slope of no more than 15°, and the slope of the next adjacent construction segment in the construction segment group is greater than 15°, sum the construction lengths of the construction segment group. If the sum is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, then i1 is selected; otherwise, with the minimum total welding cost as the objective function, i2 and i3 are optimized to obtain the preferred welding method.

[0021] For construction sections with a slope greater than 15°, determine whether the slope range of the construction section is greater than 15° and less than 30°. If so, use the minimum total cost of welding project as the objective function to optimize i2 and i3 to obtain the optimal welding method, and then jump to S5. Otherwise, jump to S4.

[0022] S4. For construction sections with a slope of not less than 30°, determine the length information. If the length information of the construction section is less than 50m, then i4 is selected as the preferred welding method. Otherwise, with the minimum total cost of welding project as the objective function, i2 and i3 are optimized to obtain the preferred welding method.

[0023] S5. Based on the preferred welding method obtained in step S3, determine whether to convert the welding method for construction sections with different welding methods based on the conversion cost. If not, directly use the welding method obtained in step S3 as the final welding method for construction sections with a slope greater than or equal to 15°. Otherwise, use the welding method converted in step S3 as the final welding method for construction sections with a slope greater than or equal to 15°.

[0024] In some embodiments, in S2, the specific process of selecting a welding method from the preliminary welding method based on the welding cost curve, according to cost constraints, is as follows:

[0025] If the length information of the construction section is that the sum of the lengths is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, then i1 is selected.

[0026] If the sum of the lengths of the construction section is less than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, or less than the smaller of S1 and S2, then i2 and i3 are optimized with the goal of minimizing the total welding cost. If the sum of the lengths of the construction section is between S1 and S2, then i2 is selected.

[0027] In some embodiments, the objective function is:

[0028]

[0029] In the formula: F represents the total cost of the welding project, in yuan; M represents the set of construction sections; N represents the set of welding methods; F j,i The welding cost for section j using welding method i is given, in yuan. s,j,i The auxiliary engineering cost for selecting welding method i at construction section j is expressed in yuan; r,i The rework cost for welding method i is expressed in yuan; F d,i The equipment scheduling cost for selecting welding method i is expressed in yuan; F p,i The pre-construction preparation cost for selecting welding method i is in yuan.

[0030] In some embodiments, the welding cost is calculated using the following formula:

[0031]

[0032] In the formula: F j,i,人 The labor cost for welding method i at construction section j is given, in yuan / (section·day); F j,i,机 The equipment cost for welding method i selected at construction section j is expressed in yuan / (road·day); F j,i,材 The material cost for welding method i selected at construction section j is expressed in yuan / (road·day); L j,i The construction length of section j using welding method i is expressed in km; c represents the number of weld joints per unit length, expressed in passes / km; x j,i The welding efficiency of welding method i selected at construction section j is given, expressed in passes / day; F w,j,i The unit is RMB [amount missing], which represents the cost of lost work due to force majeure when welding method i was selected for construction section j.

[0033] In some embodiments, the repair cost is calculated using the following formula:

[0034]

[0035] In the formula: F r,i,人 The labor cost for welding method i selected for the rework process is expressed in yuan / (way·day); F r,i,机 The equipment cost for selecting welding method i in the rework process is expressed in yuan / (way·day); F r,i,材 The material cost for welding method i selected during the rework process is expressed in yuan per (laboratory / day); L j,i The construction length of section j using welding method i is expressed in km; c represents the number of weld joints per unit length, expressed in passes / km; x j,i The welding efficiency of welding method i selected at construction section j is given, expressed in passes / day; rp i Let be the probability of rework for welding method i, expressed as %.

[0036] In some embodiments, the pre-construction preparation costs are calculated using the following formula:

[0037] F p,i =F t,i +F e,i ;

[0038] In the formula: F t,i The training cost for welders using welding method i before construction is expressed in yuan; F e,i The fee for the welder's examination for welding method i is in yuan.

[0039] In some embodiments, the constraints of the objective function include:

[0040] Slope constraints of construction section:

[0041] ε θ,i =a θ,i εi∈N;

[0042] Where: ε θ,i For a construction section with a slope of θ, the welding method i or a can be selected. θ,i For 0-1 variables, a θ,i When the value is 1, it indicates that welding method i can be selected for the construction section with a slope of θ; otherwise, a θ,i The value is 0; ε is the set of welding methods;

[0043] Special terrain constraints, including water network sections and river crossings:

[0044] ε ψ,i =b ψ,i εi∈N;

[0045] Where: ε ψ,i For special terrain features, welding methods i and b can be selected at point ψ. ψ,i This is a 0-1 variable. A value of 1 indicates that welding method i can be selected at the special terrain ψ; otherwise, the value is 0.

[0046] Atmospheric relative humidity constraint:

[0047]

[0048] In the formula: ξ ah The relative humidity of the atmosphere, in %. The maximum permissible atmospheric relative humidity during construction, expressed in %;

[0049] Wind speed constraints:

[0050]

[0051] Where: WS i The wind speed during welding method i is measured in m / s. The maximum permissible wind speed for welding method i is given in m / s.

[0052] Pipe constraints:

[0053] ε m,i =c m,i ε;

[0054] Where: ε m,i For pipes with a specification of m, the welding methods i and c can be selected. m,iThis is a 0-1 variable. A value of 1 indicates that the pipe with pipe specification m can be welded using welding method i; otherwise, the value is 0.

[0055] Pipe diameter and wall thickness constraints:

[0056] ε g,i =e g,i ε;

[0057] Where: ε g,i For a pipe diameter and wall thickness of g, the available welding methods are i and e. g,i This is a 0-1 variable. When the value is 1, it indicates the welding method i that can be selected when the pipe diameter and wall thickness are g; otherwise, the value is 0.

[0058] This invention also discloses a system for selecting welding methods for natural gas pipelines in mountainous areas, comprising:

[0059] The preliminary welding method determination module is used to determine the preliminary welding method suitable for welding mountain pipelines in the construction section based on the obtained terrain conditions, slope information, and length information of the construction section.

[0060] The recommendation module is used to select a recommended method for the construction section from the preliminary welding methods based on the terrain conditions and the slope information.

[0061] The final determination module is used to optimize the recommended method based on the slope information and length information of the construction section, and determine the final welding method of the construction section.

[0062] The present invention also discloses an electronic device, characterized in that it includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform a method for selecting a welding method for a mountain natural gas pipeline as described above.

[0063] The present invention also discloses a storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the aforementioned method for selecting a welding method for a mountain natural gas pipeline.

[0064] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0065] This invention fully considers the influence of factors such as economy, terrain and pipe material on the selection of welding methods, and can make decisions to select a more suitable welding method for mountain natural gas pipelines, providing technical support for the transportation of natural gas pipelines in mountainous areas. Attached Figure Description

[0066] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0067] Figure 1 This is a flowchart illustrating a method for selecting welding methods for mountain natural gas pipelines according to the present invention;

[0068] Figure 2 The graphs show the correlation between the cost of a single weld joint and the total welding cost. (a) shows the correlation analysis of the cost of a single weld joint; (b) shows the correlation analysis of the total welding cost. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0070] This embodiment 1 provides a method for selecting welding methods for natural gas pipelines in mountainous areas, such as... Figure 1 As shown, it includes:

[0071] Obtain the terrain conditions, slope information, and length information of the construction section, and based on the terrain conditions, slope information, and length information, obtain the preliminary welding method suitable for welding mountain pipelines in this construction section;

[0072] In some embodiments, the preliminary welding method includes fully automatic welding, combined automatic welding, single-torch automatic welding, and prefabricated automatic welding, and the fully automatic welding, combined automatic welding, single-torch automatic welding, and prefabricated automatic welding are respectively denoted as i1, i2, i3, and i4.

[0073] It should be noted that the fully automatic welding refers to automatic welding in which the root welding uses an internal welding machine and the hot welding and filling / covering welding use a double-torch external welding machine (i.e., internal welding machine + double-torch external welding machine); the combined automatic welding is a term for the combined use of manual welding rod welding or semi-automatic welding root welding and fully automatic welding filling / covering welding. The development of combined automatic welding has improved the utilization rate of fully automatic welding in the entire welding process and has the advantage of lower requirements for operating conditions compared to fully automatic welding.

[0074] Based on the terrain conditions and slope information, select the recommended method for this construction section from the preliminary welding methods;

[0075] In some embodiments, the recommended method is selected based on the following constraints:

[0076] When the slope information indicates a terrain slope of less than 15°, the recommended methods include i1, i2, and i3;

[0077] When the terrain angle is less than 15°, terrain conditions do not need to be considered.

[0078] When the slope information is a terrain slope greater than or equal to 15°, and the terrain is a short steep slope section or a river pipe jacking tunnel, the recommended methods include i2, i3 and i4;

[0079] When the terrain is a long ridge or a transverse slope, the recommended methods include i1 and i3;

[0080] When the terrain involves large-scale river excavation and road crossings, the recommended methods include i1, i2, and i3;

[0081] When the terrain is a mountain tunnel, the recommended methods include i1 and i4.

[0082] In the three terrain conditions mentioned above (long mountain ridges or transverse slopes, large river excavations and road crossings, and mountain tunnels), slope information does not need to be considered, which allows for a faster determination of the recommended method.

[0083] The recommended method is optimized based on the slope and length information of the construction section to determine the final welding method for the construction section.

[0084] In some embodiments, the specific process of optimizing the recommendation method based on the slope information and length information of the construction section is as follows:

[0085] S1. Iterate through the slope and length information of the construction section and determine whether the slope of each section of the construction section is less than 15°. If so, jump to S2; otherwise, jump to S3.

[0086] S2. Based on cost constraints, select the preferred welding method from the preliminary welding methods according to the welding cost curve as the final welding method;

[0087] In some embodiments, the specific process of selecting a welding method from the preliminary welding method based on the welding cost curve, under cost constraints, is as follows:

[0088] If the length information of the construction section is that the sum of the lengths is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, then i1 is selected.

[0089] If the sum of the lengths of the construction section is less than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, or less than the smaller of S1 and S2, then i2 and i3 are optimized with the goal of minimizing the total welding cost. If the sum of the lengths of the construction section is between S1 and S2, then i2 is selected.

[0090] Here, the horizontal axis of the welding cost curve represents the construction distance in km, and the vertical axis represents the total welding cost in ten thousand yuan. Therefore, when comparing the sum of lengths with S1, S2, and S3, we are referring to comparing them on the horizontal axis.

[0091] The sources of total welding costs include: literature review "Economic Benefit Analysis of Automatic and Semi-Automatic Welding in Long-Distance Pipeline Engineering", Liaoning Oil Construction "Welding Calculation of Shale Gas Gathering and Transmission Trunk Line Project in Weiyuan and Luzhou Blocks", and "Temporary Pricing Basis for Automatic Welding of Long-Distance Pipeline Trench Combination by Southwest Oil and Gas Field Branch".

[0092] That is, if the slope of each section of the construction segment is less than 15°, and the sum of the lengths of the construction segments is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, then i1 is selected.

[0093] If the slope of each section of the construction project is less than 15°, and the sum of the lengths of the construction sections is less than or equal to the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, then i2 and i3 are optimized with the minimum total welding cost as the objective function.

[0094] It should be noted that the i1 welding cost curve, i2 welding cost curve, and i3 welding cost curve correspond to the welding cost curves of fully automatic welding, combined automatic welding, and single-torch automatic welding, respectively.

[0095] As explained in the preceding model parameter explanation, the welding cost for a given welding method can be considered a function of the construction distance. A corresponding welding cost model was developed in the mathematical modeling software GAMS to derive the welding cost for different construction distances, resulting in corresponding welding cost curves.

[0096] In some embodiments, the objective function is:

[0097]

[0098] In the formula: F represents the total cost of the welding project, in yuan; M represents the set of construction sections; N represents the set of welding methods; F j,iThe welding cost for section j using welding method i is given, in yuan. s,j,i The auxiliary engineering cost for selecting welding method i at construction section j is expressed in yuan; r,i The rework cost for welding method i is expressed in yuan; F d,i The equipment scheduling cost for selecting welding method i is expressed in yuan; F p,i The pre-construction preparation cost for selecting welding method i is in yuan.

[0099] Auxiliary engineering cost F s,j,i The data includes many items and is quite complex. No specific statistics were compiled on-site; only some values ​​provided for reference are available.

[0100] Equipment scheduling cost F for welding method i d,i Since the equipment scheduling costs vary for different welding methods, and no specific statistics have been compiled, we can only provide some values ​​for reference, such as the approximate cost of equipment scheduling for i2 per operation.

[0101] Here, welding method i is one of i1, i2, i3, or i4. In some embodiments, the welding cost is calculated using the following formula:

[0102]

[0103] In the formula: F j,i,人 The labor cost for welding method i at construction section j is given, in yuan / (section·day); F j,i,机 The equipment cost for welding method i selected at construction section j is expressed in yuan / (road·day); F j,i,材 The material cost for welding method i selected at construction section j is expressed in yuan / (road·day); L j,i The construction length of section j using welding method i is expressed in km; c represents the number of weld joints per unit length, expressed in passes / km; x j,i The welding efficiency of welding method i selected at construction section j is given, expressed in passes / day; F w,j,i The unit is RMB [amount missing], which represents the cost of lost work due to force majeure when welding method i was selected for construction section j.

[0104] In some embodiments, the repair cost is calculated using the following formula:

[0105]

[0106] In the formula: F r,i,人 The labor cost for welding method i selected for the rework process is expressed in yuan / (way·day); F r,i,机 The equipment cost for selecting welding method i in the rework process is expressed in yuan / (way·day); F r,i,材The material cost for welding method i selected during the rework process is expressed in yuan per (laboratory / day); L j,i The construction length of section j using welding method i is expressed in km; c represents the number of weld joints per unit length, expressed in passes / km; x j,i The welding efficiency of welding method i selected at construction section j is given, expressed in passes / day; rp i Let be the probability of rework for welding method i, expressed as %.

[0107] In some embodiments, the pre-construction preparation costs are calculated using the following formula:

[0108] F p,i =F t,i +F e,i (4);

[0109] In the formula: F t,i The training cost for welders using welding method i before construction is expressed in yuan; F e,i The fee for the welder's examination for welding method i is in yuan.

[0110] In some embodiments, the constraints of the objective function include:

[0111] Slope constraints of construction section:

[0112] ε θ,i =a θ,i εi∈N(5);

[0113] Where: ε θ,i For a construction section with a slope of θ, the welding method i or a can be selected. θ,i For 0-1 variables, a θ,i When the value is 1, it indicates that welding method i can be selected for the construction section with a slope of θ; otherwise, a θ,i The value is 0; ε is the set of welding methods;

[0114] The formula means the following: Assume ε contains {i1, i2, ..., i} n When θ is less than 15°, The value of θ is 1, and the values ​​of the others are 0. That is, when θ is less than 15°, only i1, i2, and i3 will be compared for subsequent welding methods, and the other welding methods will not be compared.

[0115] Special terrain constraints, including water network sections and river crossings:

[0116] ε ψ,i =b ψ,i εi∈N(6);

[0117] Where: ε ψ,iFor special terrain features, welding methods i and b can be selected at point ψ. ψ,i This is a 0-1 variable. A value of 1 indicates that welding method i can be selected at the special terrain ψ; otherwise, the value is 0.

[0118] The unique terrain here includes long ridges or transverse slopes, large-scale river excavations and road crossings, and mountain tunnels. That is, assuming ε contains {i1, i2, ..., i...} n When the terrain consists of long ridges or transverse slopes, The value of is 1, and the rest are 0.

[0119] Atmospheric relative humidity constraint:

[0120]

[0121] Equation (7) states that if the relative humidity of the atmosphere exceeds the maximum allowable value during welding method i, welding should not be performed without effective protective measures; where: ξ ah The relative humidity of the atmosphere, in %. The maximum permissible atmospheric relative humidity during construction, expressed in %;

[0122] Wind speed constraints:

[0123]

[0124] Equation (8) states that if the wind speed exceeds the maximum allowable value for welding method i during construction, welding should not be performed without effective protective measures; where: WS i The wind speed during welding method i is measured in m / s. The maximum permissible wind speed for welding method i is given in m / s.

[0125] Pipe constraints:

[0126] ε m,i =c m,i ε(9);

[0127] Where: ε m,i For pipes with a specification of m, the welding methods i and c can be selected. m,i This is a 0-1 variable. A value of 1 indicates that the pipe with pipe specification m can be welded using welding method i; otherwise, the value is 0.

[0128] Different pipe specifications require different welding methods. Based on expert advice and available field data, this study primarily focuses on pipes of specification X80-1219, for which the following five welding methods are available:

[0129] Method 1: Fully automatic internal welding + dual welding torch external welding

[0130] Method 2: Combined Automatic Welding

[0131] Method 3: Single-torch automatic welding

[0132] Method 4: Gas-shielded semi-automatic welding

[0133] Method 5: Manual welding

[0134] Other specifications: X70-1016

[0135] Method 1: Fully automatic internal welding + dual welding torch external welding

[0136] Method 2: Combined Automatic Welding

[0137] Method 3: Gas-shielded semi-automatic welding

[0138] Method 4: Manual welding

[0139] X65-914

[0140] Method 1: Combined Automatic Welding

[0141] Method 2: Single-torch automatic welding

[0142] Method 3: Gas-shielded semi-automatic welding

[0143] Method 4: Manual welding

[0144] Pipe diameter and wall thickness constraints:

[0145] ε g,i =e g,i ε(10);

[0146] Where: ε g,i For a pipe diameter and wall thickness of g, the available welding methods are i and e. g,i This is a 0-1 variable. When the value is 1, it indicates the welding method i that can be selected when the pipe diameter and wall thickness are g; otherwise, the value is 0.

[0147] The above process is the initial welding method selection process for construction sections where the slope is all less than 15°. For construction sections with a slope greater than 15°, the following process is the initial welding method selection process.

[0148] S3. For a construction segment group consisting of multiple consecutive construction segments with a slope of no more than 15°, and the slope of the next adjacent construction segment in the construction segment group is greater than 15°, sum the construction lengths of the construction segment group. If the sum is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve, then i1 is selected; otherwise, with the minimum total welding cost as the objective function, i2 and i3 are optimized to obtain the preferred welding method.

[0149] That is, if the slope of the first n construction sections is Xn ≤15°, slope X of the (n+1)th construction segment n+1 If the angle is greater than 15°, then the construction lengths of the first n construction segments are summed. If the summation is greater than S1, then i1 is selected; otherwise, i2 and i3 are selected with the goal of minimizing the total cost of the welding project.

[0150] For construction sections with a slope greater than 15°, determine whether the slope range of the construction section is greater than 15° and less than 30°. If so, use the minimum total cost of welding project as the objective function to optimize i2 and i3 to obtain the optimal welding method, and then jump to S5. Otherwise, jump to S4.

[0151] That is, if the slope of the (n+1)th construction segment is 15° <X n+1 If the angle is less than 30°, then i2 and i3 are optimized with the objective function of minimizing the total cost of the welding project.

[0152] S4. For construction sections with a slope of not less than 30°, determine the length information. If the length information of the construction section is less than 50m, then i4 is selected as the preferred welding method. Otherwise, with the minimum total cost of welding project as the objective function, i2 and i3 are optimized to obtain the preferred welding method.

[0153] That is, if the slope of the (n+1)th construction segment is X n+1 If the angle is ≥30°, then the length of the (n+1)th construction segment is determined:

[0154] If L Xn+1 If the cost is less than 50m, then i4 is selected; otherwise, i2 and i3 are selected with the objective function of minimizing the total cost of the welding project.

[0155] Repeat the above steps to determine and select the welding method for all construction sections.

[0156] S5. Based on the preferred welding method obtained in step S3, determine whether to convert the welding method for construction sections with different welding methods based on the conversion cost. If not, directly use the welding method obtained in step S3 as the final welding method for construction sections with a slope greater than or equal to 15°. Otherwise, use the welding method converted in step S3 as the final welding method for construction sections with a slope greater than or equal to 15°.

[0157] If two adjacent construction sections have different welding methods, and the cost increases after conversion, the welding method will not be converted; if the cost decreases after conversion, the welding method will be converted for the latter construction section.

[0158] For example, suppose the slope of construction section 1 is 13° (less than 15°), the construction length is x km, and the selected welding method is i3; the slope of construction section 2 is 20°, and both welding methods i2 and i3 can be selected. If only the actual length of construction section 2 is considered, choosing i2 is more economical. However, in the actual construction process, the personnel deployment costs, machinery and equipment relocation costs, and transportation costs incurred during the switching of welding methods need to be considered. If these costs are taken into account, the cost of using i2 for construction section 2 is still lower than that of i3, then the welding method for construction section 2 does not need to be changed. Otherwise, the welding method for construction section 2 needs to be changed from the initial i2 to i3, that is, construction sections 1 and 2 maintain the same welding method.

[0159] Therefore, the 'conversion' considers the specific welding method to be selected for construction section 2 when there is a slope transition, i.e., when the slope of construction section 1 is less than 15° and the slope of construction section 2 is greater than 15°. It cannot be simply based on minimizing the construction cost of construction section 2, but should take into account the relevant conversion costs in the actual process and consider the overall situation.

[0160] As can be seen from the above, the conversion of welding methods is an adjustment made to the welding methods within the context of the actual engineering background. There will be no situation where unsuitable welding methods are used for pipe welding in certain construction sections. At the same time, in actual construction, the costs associated with equipment scheduling and other expenses resulting from welding method conversion are a significant portion and must therefore be considered in the model.

[0161] Both the cost of a single weld joint and the total welding cost are influenced by multiple factors. To assess the correlation between welding costs and factors such as welding efficiency, Spearman correlation analysis was used to evaluate the correlation of combined automated welding. The evaluation results are as follows: Figure 2 As shown.

[0162] Welding costs refer to the cost of a single weld joint, considering the direct cost of the welding method. Its cost function includes labor, machinery, materials, pre-construction preparation costs, the number of weld joints per unit length, construction length, and welding efficiency. It does not take into account costs associated with earthwork, equipment scheduling, and other expenses incurred throughout the entire project.

[0163] Depend on Figure 2It can be seen that, except for welding efficiency, all other factors are positively correlated with the cost per weld and the total welding cost. Specifically, the number of welds per unit length, pre-construction preparation costs, and material costs show a moderate correlation with the cost per weld and the total welding cost, indicating that these factors influence costs to some extent. Construction length, labor costs, and equipment costs show a strong correlation with the cost per weld and the total welding cost, indicating that these factors have a more significant impact on costs. Welding efficiency shows a moderate negative correlation with both the cost per weld and the total welding cost, suggesting that improving welding efficiency can effectively reduce welding costs. Spearman correlation analysis allows for a more accurate understanding of the importance of each factor in welding costs, providing theoretical support for welding cost control. Correlation analysis clarifies the extent of each factor's impact on welding costs, which is beneficial for construction planning.

[0164] Next, the invention will be illustrated through a specific implementation example.

[0165] In a specific embodiment, taking a natural gas pipeline in a mountainous area as an example, the welding method of this invention is adopted. In this embodiment, the resource allocation of fully automatic welding, semi-automatic welding, and combined automatic welding units is shown in Tables 1-9. During construction, the transportation and relocation costs of machinery and equipment are 34,000 yuan / km, and the personnel dispatch cost is 1,850 yuan / km. Among them, the resource allocation of fully automatic welding and semi-automatic welding is based on the construction of a natural gas transmission pipeline in Xinjiang, with a comprehensive consideration of 85 welding joints per kilometer. The daily construction efficiency of fully automatic welding is 43 joints, and the monthly construction efficiency is 11.634km; the daily construction efficiency of semi-automatic welding is 20 joints, and the monthly construction efficiency is 5.412km; the resource allocation of combined automatic welding is based on a shale gas technical trunk line project in a certain block, with a comprehensive consideration of 105 welding joints per kilometer, an average of 1.4 joints / day, and a construction period of 75 days per kilometer.

[0166] Table 1 Daily Labor Costs for Fully Automated Welding

[0167]

[0168] Table 2 Daily Equipment Costs for Fully Automated Welding

[0169]

[0170] Table 3. Material Costs for Fully Automatic Welding

[0171] Material category Full-automatic welding machine accessories Equipment oil Hardware materials Mixed gas Oxygen Acetylene gas Price (yuan / km) 38340 40500 4400 15150 700 700

[0172] Table 4 Daily Labor Costs for Semi-Automatic Welding

[0173]

[0174]

[0175] Table 5 Daily Equipment Costs for Semi-Automatic Welding

[0176]

[0177] Table 6. Material Costs for Semi-Automatic Welding

[0178] Material category Semi-automatic welding machine accessories Equipment oil Hardware materials Argon Oxygen Acetylene gas Price (yuan / km) 570 40500 4400 4800 800 800

[0179] Table 7 Daily Labor Costs for Combined Automatic Welding

[0180] Labor category Team leader Technician Quality inspector Safety inspector Pipe worker Electric welder Hoisting Repair General worker Shift worker Quantity 1 1 1 1 2 8 1 1 6 1 Unit price 700 500 400 400 600 700 500 500 240 200 Total price 700 500 400 400 1200 5600 500 500 1440 200

[0181] Table 8 Daily Equipment Costs for Combined Automatic Welding

[0182] Mechanical category Excavator Folded wall engineering vehicle Internal combustion welding machine Electric king single-gun external welding machine Electric welding rod drying box Truck External counter Quantity 1 3 2 6 2 2 75 Unit price 1456 1100 130 720 32.4 443 10 Total price 1456 3300 260 4320 64.8 886 750

[0183] Table 9. Cost of Materials for Combined Automatic Welding

[0184] Material category Low-hydrogen welding wire Primer electrode Mixed gas Argon Oxygen Acetylene gas Quantity 1681 155 271 116 93 31 Unit price 73 59 91 79.6 5 19.5 Total price 122713 9145 24661 9234 465 605

[0185] Table 10 summarizes the construction costs of fully automatic and semi-automatic welding using the unit price method, while Table 11 shows the specific costs of combined automatic welding. Table 12 calculates the construction cost per weld joint for each welding method based on the specific costs and construction efficiency. Table 13 shows the calculated costs per weld joint and total welding cost.

[0186] Table 10 Construction Costs Per Kilometer for Fully Automated Welding and Semi-Automatic Welding

[0187] Expense category Labor cost Equipment cost Material cost Total Full-automatic welding 33769 87876 99090 220735 Semi-automatic welding 66087 73015 51070 190172

[0188] Table 11. Construction cost per kilometer for combined automatic welding systems

[0189] Expense category Labor cost Equipment cost Material cost Total Combined automatic welding 858000 979132 762966 2600098

[0190] Table 12 Construction Cost of Single Weld Joint for Various Welding Methods

[0191] Expense category Labor cost (yuan / section.day) Equipment cost (yuan / section.day) Material cost (yuan / section.day) Total (yuan / section.day) Full-automatic welding 202 527 594 1323 Semi-automatic welding 186 206 144 536 Combined automatic welding 109 124 97 330

[0192] Table 13 Calculation of Single Weld Joint and Total Welding Costs

[0193] Expense category Single-welding opening cost Total welding cost Error Full-automatic welding 2615 222294 0.7％ Semi-automatic welding 1059 193630 1.8％ Combined automatic welding 24750 2598750 0.05％

[0194] The relevant parameters for each welding method were set, and the results are shown in Tables 14 and 15. The resulting welding economic matrix is ​​shown in Table 16.

[0195] Table 14 Parameter Settings

[0196]

[0197] Table 15 Welding efficiency settings

[0198]

[0199] Table 16 Welding Economic Matrix

[0200]

[0201] Table 16 shows that in plain sections with a slope ≤ 15°, combined automatic welding is recommended when L ≤ 3km; single-torch automatic welding is recommended when 3 ≤ L ≤ 5km; and fully automatic welding is recommended when L ≥ 5km. In construction sections with a slope ≤ 30° and a gradient between 15° and 15°, combined automatic welding is recommended when L ≤ 2.1km; and single-torch automatic welding is recommended when L ≥ 2.1km. In steep slopes with a gradient > 30°, prefabricated automatic welding is recommended when L ≤ 0.05km; combined automatic welding is recommended when 0.05 ≤ L ≤ 1km; and single-torch automatic welding is recommended when L ≥ 1km.

[0202] Welding method decisions were made for construction sections of a long-distance pipeline with slopes ≤15° (L=0.99km), ≤30° (L=2.11km), and >30° (L=0.99km). The results are shown in Table 17-19. The welding methods considered included fully automatic welding, combined automatic welding, single-torch automatic welding, and prefabricated automatic welding.

[0203] Table 17 Decision-making for welding methods with a slope ≤15°

[0204]

[0205] Table 18 Decision-making for welding methods with a slope ≤ 30°

[0206]

[0207]

[0208] Table 19 Decision-making for welding methods when the slope is >30°

[0209]

[0210] In summary, this invention can recommend welding methods for construction sections with different slopes and lengths, and it represents a significant improvement over existing technologies.

[0211] In some embodiments, a system for selecting welding methods for mountain natural gas pipelines is also disclosed, comprising:

[0212] The preliminary welding method determination module is used to determine the preliminary welding method suitable for welding mountain pipelines in the construction section based on the obtained terrain conditions, slope information, and length information of the construction section.

[0213] The recommendation module is used to select a recommended method for the construction section from the preliminary welding methods based on the terrain conditions and the slope information.

[0214] The final determination module is used to optimize the recommended method based on the slope information and length information of the construction section, and determine the final welding method of the construction section.

[0215] In some embodiments, an electronic device is also disclosed, including at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform a method for selecting a welding method for a mountain natural gas pipeline as described above.

[0216] In some embodiments, a storage medium storing a computer program is also disclosed, characterized in that the computer program, when executed by a processor, implements the aforementioned method for selecting a welding method for a mountain natural gas pipeline.

[0217] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for selecting a welding method for a mountain natural gas pipeline, characterized by, The method comprises the following steps: obtaining the topography, slope information and length information of a construction section, and obtaining a preliminary welding method suitable for welding a mountain pipeline in the construction section according to the topography, slope information and length information; selecting a recommended method for the construction section from the preliminary welding method according to the topography and slope information; optimizing the recommended method according to the slope information and length information of the construction section, and determining a final welding method for the construction section.

2. The method of claim 1, wherein, The preliminary welding method comprises full-automatic welding, combined automatic welding, single-torch automatic welding and prefabricated automatic welding, and the full-automatic welding, combined automatic welding, single-torch automatic welding and prefabricated automatic welding are respectively denoted as i1, i2, i3 and i4.

3. The method of claim 2, wherein the method is characterized by: The recommended method is selected according to the following constraints: when the slope information is that the topography slope is less than 15°, the recommended method comprises i1, i2 and i3; when the slope information is that the topography slope is greater than or equal to 15° and the topography is a short steep slope section or a river pipe-jacking tunnel, the recommended method comprises i2, i3 and i4; when the topography is a long-distance ridge or a cross-slope zone, the recommended method comprises i1 and i3; when the topography is a river large excavation and road crossing section, the recommended method comprises i1, i2 and i3; when the topography is a mountain tunnel, the recommended method comprises i1 and i4.

4. The method of claim 2, wherein the method is characterized by: The specific process of optimizing the recommended method according to the slope information and length information of the construction section is as follows: S1, traversing the slope information and length information of the construction section, and judging whether the slope of each section of the construction section is less than 15°, if yes, jumping to S2, otherwise, jumping to S3; S2, selecting an optimized welding method as the final welding method from the preliminary welding method according to a welding cost curve based on a cost constraint; S3, for a construction section group composed of continuous multiple sections whose slopes are all not greater than 15° and an adjacent next section whose slope is greater than 15°, summing the construction lengths of the construction section group, if greater than an intersection point S1 of an i1 welding cost curve and an i2 welding cost curve, i1 is selected, otherwise, optimizing i2 and i3 to obtain an optimized welding method with the minimum total welding engineering cost as an objective function; for a construction section whose slope is greater than 15°, judging whether the slope range of the construction section is within greater than 15° and less than 30°, if yes, optimizing i2 and i3 to obtain an optimized welding method with the minimum total welding engineering cost as an objective function, and then jumping to S5, otherwise, jumping to S4; S4, for a construction section whose slope is not less than 30°, judging the length information of the construction section, if the length information of the construction section is that the length is less than 50 m, i4 is selected as the optimized welding method, otherwise, optimizing i2 and i3 to obtain an optimized welding method with the minimum total welding engineering cost as an objective function. S5, based on the conversion cost, judging whether to convert the welding mode of the construction section with different welding modes, if not, directly taking the welding mode obtained in step S3 as the final welding mode of the construction section with slope greater than or equal to 15°, otherwise, taking the welding mode converted in step S3 as the final welding mode of the construction section with slope greater than or equal to 15°.

5. The method of claim 4, wherein the method is characterized by: In S2, based on the cost constraint, the specific process of selecting the welding mode from the preliminary welding mode according to the welding cost curve is: If the length information of the construction section is the sum of lengths and is greater than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve, i1 is selected; If the length information of the construction section is the sum of lengths and is less than the intersection point S1 of the i1 welding cost curve and the i2 welding cost curve and the intersection point S2 of the i1 welding cost curve and the i3 welding cost curve or less than the smaller one of S1 and S2, i2 and i3 are optimized with the minimum total welding engineering cost as the objective function; if the length information of the construction section is the sum of lengths between S1 and S2, i2 is selected.

6. A method of selecting a welding method for a mountain natural gas pipeline according to claim 4 or 5, characterized in that, The objective function is: Wherein: F is the total welding engineering cost, unit: yuan; M is the set of construction sections; N is the set of welding methods; F j,i is the welding cost of welding method i selected at construction section j, unit: yuan; F s,j,i is the auxiliary engineering cost of welding method i selected at construction section j, unit: yuan; F r,i is the rework cost of welding method i selected, unit: yuan; F d,i is the cost of using the welding equipment i, in yuan. F p,i The construction preparation cost of the welding method i is 1000 yuan.

7. The method of claim 6, wherein the method is characterized by: The welding cost is calculated by the following formula: In the formula: F j,i,人 F is the labor cost of selecting welding mode i at construction section j, with unit of yuan / (lane·day); F j,i,机 F is the equipment cost of selecting welding mode i at construction section j, with unit of yuan / (lane·day); F j,i,材 F is the material cost of selecting welding mode i at construction section j, with unit of yuan / (lane·day); L j,i L is the construction length of selecting welding mode i at construction section j, with unit of km; c is the number of welds per unit length, with unit of lane / km; x j,i F is the welding efficiency of selecting welding mode i at construction section j, with unit of lane / day; F w,j,i F is the idle cost of selecting welding mode i at construction section j due to force majeure, with unit of yuan.

8. The method of claim 6, wherein the method is characterized by: The repair cost is calculated by the following formula: In the formula: F r,i,人 The labor cost for welding method i selected for the rework process is expressed in yuan / (way·day); F r,i,机 The equipment cost for selecting welding method i in the rework process is expressed in yuan / (way·day); F r,i,材 The material cost for welding method i selected during the rework process is expressed in yuan per (laboratory / day); L j,i The construction length of section j using welding method i is expressed in km; c represents the number of weld joints per unit length, expressed in passes / km; x j,i The welding efficiency of welding method i selected at construction section j is given, expressed in passes / day; rp i Let be the probability of rework for welding method i, expressed as %.

9. The method of claim 1, wherein the method is characterized by: The construction preparation cost is calculated by the following formula: F p,i = F t,i + F e,i ; In the formula: F t,i is the welder training cost of welding method i before construction, in yuan; F e,i is the welder examination cost of welding method i, in yuan.

10. The method of claim 6, wherein the method is characterized by: The constraint conditions of the objective function include: Construction section slope constraint: ε θ,i = a θ,i εi∈N; wherein: ε θ,i is the welding mode i available for the construction section with slope θ; a θ,i is a 0-1 variable, a θ,i is 1, indicating that the welding mode i is available for the construction section with slope θ, otherwise, a θ,i is 0; ε is the set of welding modes; Special terrain constraint, the special terrain includes water network section and river crossing: ε ψ,i = b ψ,i εi∈N; wherein: ε ψ,i is the welding mode i available at the special terrain ψ; b ψ,i is a 0-1 variable, which has a value of 1 if the welding mode i is available at the special terrain ψ, and otherwise has a value of 0; Atmospheric relative humidity constraint: wherein: ξ ah is the relative atmospheric humidity, in %; is the maximum relative atmospheric humidity allowed for the construction, in %; Wind speed constraint: where: WS i is the wind speed during the welding mode i construction process, m / s; is the maximum wind speed allowed for the welding mode i construction, m / s; Pipe material constraint: ε m,i = c m,i ε; wherein: ε m,i i; c is the welding mode available for the pipe with pipe specification m; and m,i is a 0-1 variable, and when the value is 1, it indicates that the welding mode i is available for the pipe with pipe specification m; otherwise, the value is 0. Pipe diameter and wall thickness constraint: ε g,i = e g,i ε; wherein: ε g,i is the weld type i available for pipe diameter wall thickness g; e g,i is a 0-1 variable, with value 1 indicating that the weld type i is available for pipe diameter wall thickness g; otherwise, the value is 0.

11. A system for selecting a welding method for a mountain natural gas pipeline, characterized by, including: A preliminary welding mode establishing module is configured to obtain a preliminary welding mode suitable for welding the mountain pipeline in the construction section according to the obtained topographic condition, slope information and length information of the construction section; A recommendation module is configured to select a recommended method for the construction section from the preliminary welding mode according to the topographic condition and the slope information; A final determination module is configured to optimize the recommended method according to the slope information and the length information of the construction section and determine the final welding mode of the construction section.

12. An electronic device, comprising: The computer program is executed by the processor to implement the method for selecting the welding mode of the mountain natural gas pipeline according to any one of claims 1 to 11.

13. A storage medium storing a computer program, characterized in that, The computer program is executed by the processor to implement the method for selecting the welding mode of the mountain natural gas pipeline according to any one of claims 1 to 11.

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