Cable current-carrying estimation method and device, computer equipment, readable storage medium and program product
By combining a quasi-three-dimensional thermal circuit model with soil stratification parameters, the problem of insufficient calculation accuracy for directional drilling cable laying was solved, enabling more accurate current-carrying capacity assessment and improving the safety and stability of the power grid.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-29
- Publication Date
- 2026-04-07
AI Technical Summary
Traditional methods for calculating the current-carrying capacity of cables laid by directional drilling neglect the influence of soil stratification and underground constant temperature layers, resulting in insufficient calculation accuracy and failing to meet engineering requirements, thus affecting the safety and stability of the cables.
A quasi-three-dimensional thermal circuit model was used to obtain soil stratification parameters and a quasi-three-dimensional thermal circuit model of directional drilling cable laying. Combined with the influence of soil stratification and underground constant temperature layer, the axial and radial thermal resistance parameters of cable micro-elements were calculated, the temperature distribution was determined, and the current carrying capacity was determined at the preset temperature.
This improves the accuracy of current-carrying capacity calculation for directional drilling cables, enhancing the safety and stability of the power grid.
Smart Images
Figure CN121809160A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for estimating cable current carrying capacity. Background Technology
[0002] With the continuous surge in societal electricity demand, the high load density faced by cable operations is becoming increasingly prominent. Conductors per unit cross-section must carry higher currents, leading to a significant increase in losses due to Joule heating and continuous heat accumulation. Cable insulation layers (such as XLPE cross-linked polyethylene and PVC polyvinyl chloride) are extremely sensitive to temperature. When the conductor temperature exceeds the insulation material's tolerance limit, the insulation layer ages and degrades rapidly, resulting in a significant decrease in insulation resistance and ultimately causing serious accidents such as insulation breakdown, short circuits, and even fires. Therefore, accurate assessment of the current-carrying capacity of cable lines in this scenario has received widespread attention.
[0003] Traditional techniques mainly include the finite element method (FEM) and analytical methods. The FEM requires establishing complex geometric models for calculation, and its speed cannot meet the computational needs of engineering applications. Analytical methods offer faster calculation speeds, but their accuracy depends on the precision of the cable heat transfer model. Soil thermal resistance, as the largest thermal resistance parameter along the heat transfer path of directional drilling cables, plays a decisive role in the accuracy of cable thermal assessment. Due to the characteristics of deep burial and long spans in directional drilling cables, the thermal conductivity of the soil varies at different depths under the influence of rainfall, weather temperature, groundwater, and the cable's own heat generation, requiring further analysis and modeling.
[0004] However, traditional methods are designed for horizontally laid cables, which are relatively shallow. Therefore, they treat the external soil medium as a semi-infinite domain and ignore the influence of the underground constant temperature layer on the cable conductor temperature calculation. This results in larger calculation errors when the calculation model is applied to directional drilling cable laying scenarios. Summary of the Invention
[0005] Therefore, it is necessary to provide a cable current carrying capacity estimation method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can improve the accuracy of current carrying capacity calculation for directional drilling cables, in order to address the aforementioned technical problems.
[0006] In a first aspect, this application provides a method for estimating cable current carrying capacity, the method comprising:
[0007] Obtain soil stratification parameters and a quasi-three-dimensional thermal path model for directional drilling cable laying; wherein, the soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions; the quasi-three-dimensional thermal path model includes the cable element length, the radial heat transfer path from the cable body of the cable element to the environmental boundary, and the axial heat transfer path of the cable element.
[0008] Based on the length of the cable element and the axial heat transfer path, the axial thermal resistance parameter of each cable element is determined; based on the length of the cable element and the radial heat transfer path, the heat source parameter of each cable element and the radial thermal resistance parameter corresponding to each layer of the cable body to the pipe structure of each cable element are determined.
[0009] For each cable micro-element, the type of the soil region to which the cable micro-element belongs is obtained; based on the average thermal conductivity corresponding to the type of soil region, the soil thermal resistance parameter of the cable micro-element is determined.
[0010] The temperature distribution of the cable micro-element is determined based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to each layer of the cable body to the pipeline structure of the same cable micro-element.
[0011] When the temperature distribution meets the preset temperature, the current that meets the preset temperature is determined as the current carrying capacity.
[0012] In one embodiment, the soil region type includes shallow soil regions and deep soil regions; obtaining soil stratification parameters includes:
[0013] Soil samples were obtained at different depths in the cable laying area;
[0014] Calculate the thermal conductivity of each of the soil samples;
[0015] The soil depth corresponding to the maximum difference in thermal conductivity between adjacent soils is determined as the critical point, and the soil region is divided into shallow soil region and deep soil region according to the critical point.
[0016] Calculate the mean thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region.
[0017] In one embodiment, the method for determining the length of the cable element includes:
[0018] Obtain the total length of the directional drilling cable;
[0019] According to the axial direction of the directional drilling cable, the directional drilling cable is divided into a target number of cable micro-elements;
[0020] The length of a cable element is determined based on the total length of the cable and the target quantity.
[0021] In one embodiment, determining the axial thermal resistance parameter of each cable element based on the cable element length and the axial heat transfer path includes:
[0022] Obtain the equivalent axial thermal conductivity and cross-sectional area of the conductor of the cable element in the axial heat transfer path;
[0023] Based on the conductor's equivalent axial thermal conductivity, the cross-sectional area, and the cable element length, the axial thermal resistance parameter of each cable element is determined.
[0024] In one embodiment, the radial heat transfer path includes a conductor, an insulation layer, and a conduit from the inside out; the radial thermal resistance parameters include conductor thermal resistance parameters, insulation layer thermal resistance parameters, conduit thermal resistance parameters, and filler material thermal resistance parameters; determining the heat source parameters of each cable micro-element and the radial thermal resistance parameters corresponding to each layer of the cable body to the conduit structure of each cable micro-element based on the cable micro-element length and the radial heat transfer path includes:
[0025] Based on the conductor parameters, the insulation layer structural parameters, and the load parameters of the cable during actual operation, the conductor loss and insulation layer loss are determined.
[0026] Based on the conductor loss, the insulation layer loss, and the cable element length, determine the heat source parameters of the cable element;
[0027] The thermal resistance parameters of the conductor are determined based on the inner and outer diameters of the conductor and the thermal conductivity of the conductor material.
[0028] Based on the inner and outer diameters of the insulating layer and the thermal conductivity of the insulating layer material, the thermal resistance parameters of the insulating layer are determined.
[0029] The thermal resistance parameters of the filling material are determined based on the inner diameter of the pipe, the outer diameter of the insulation layer, and the thermal conductivity of the filling material.
[0030] In one embodiment, obtaining the type of the soil region to which the cable micro-element belongs; and determining the soil thermal resistance parameter of the cable micro-element based on the average thermal conductivity corresponding to the type of soil region, includes:
[0031] Obtain the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary. If the distance is less than or equal to the thickness of the deep soil region, the soil region to which the cable micro-element belongs is a deep soil region. Use the average thermal conductivity of the deep soil region as the first equivalent soil thermal conductivity. Based on the first equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, determine the soil thermal resistance parameter of the cable micro-element.
[0032] When the distance is greater than the thickness of the deep soil region but less than or equal to half the sum of the thicknesses of the deep soil region and the shallow soil region, the soil region to which the cable micro-element belongs is classified as either a deep soil region or a shallow soil layer. A second equivalent soil thermal conductivity is determined based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region. The soil thermal resistance parameter of the cable micro-element is determined based on the second equivalent soil thermal conductivity, the distance, and the outer radius of the pipe.
[0033] When the distance is greater than half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the type of soil region to which the cable micro-element belongs is a deep soil region and a shallow soil layer; a second equivalent soil thermal conductivity is determined based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region; the soil thermal resistance parameter of the cable micro-element is determined based on the second equivalent soil thermal conductivity, the outer radius of the pipe, the thickness of the deep soil region and the thickness of the shallow soil region.
[0034] Secondly, this application also provides a cable current carrying capacity estimation device, the device comprising:
[0035] The acquisition module is used to acquire soil stratification parameters and a quasi-three-dimensional thermal path model of directional drilling cable laying; wherein, the soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions; the quasi-three-dimensional thermal path model includes the cable micro-element length, the radial heat transfer path from the cable body of the cable micro-element to the environmental boundary, and the axial heat transfer path of the cable micro-element.
[0036] The first determining module is used to determine the axial thermal resistance parameter of each cable micro-element based on the length of the cable micro-element and the axial heat transfer path; and to determine the heat source parameter of each cable micro-element and the radial thermal resistance parameter corresponding to each layer of the cable body to the pipe structure of each cable micro-element based on the length of the cable micro-element and the radial heat transfer path.
[0037] The second determining module is used to obtain the type of soil region to which each cable micro-element belongs; and to determine the soil thermal resistance parameter of the cable micro-element based on the average thermal conductivity corresponding to the type of soil region.
[0038] The third determining module is used to determine the temperature distribution of the cable micro-element based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to the cable body to each layer of the pipeline structure of the same cable micro-element.
[0039] The current carrying capacity is determined by the current at which the temperature distribution satisfies the preset temperature, provided that the temperature distribution satisfies the preset temperature.
[0040] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method.
[0041] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.
[0042] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described method.
[0043] The aforementioned cable current-carrying capacity estimation methods, devices, computer equipment, computer-readable storage media, and computer program products propose a quasi-three-dimensional thermal path model based on measured soil stratification parameters and incorporating radial and axial heat transfer paths. This model comprehensively considers the influence of soil stratification and underground isothermal layers, focusing on the impact of soil stratification (differences in thermal conductivity at different soil depths) on heat transfer under conditions of large burial depth and large span. Based on the soil stratification parameters and the quasi-three-dimensional thermal path model, the thermal resistance parameters of each layer of the cable structure, pipes, and filling materials, as well as the thermal resistance parameters of the soil, are calculated. Based on these thermal resistance parameters, the current-carrying capacity is determined. This addresses the problem that traditional techniques treat the soil as a semi-infinite, homogeneous medium, resulting in insufficient accuracy for directional drilling cable laying scenarios. Ultimately, this improves the accuracy of current-carrying capacity calculations for directional drilling cables, thereby enhancing the safety and stability of power grid operation. Attached Figure Description
[0044] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0045] Figure 1 This is a flowchart illustrating a cable current carrying capacity estimation method in one embodiment;
[0046] Figure 2 This is a schematic diagram of a quasi-three-dimensional thermal circuit model of a directional drilling cable laying method in one embodiment;
[0047] Figure 3 This is a schematic diagram of the process for obtaining soil stratification parameters in one embodiment;
[0048] Figure 4 This is a schematic diagram of soil stratification parameters in one embodiment;
[0049] Figure 5 This is a flowchart illustrating the process of determining the heat source parameters and radial thermal resistance parameters of each cable micro-element in one embodiment.
[0050] Figure 6 This is a schematic diagram of the shape factor method calculation in one embodiment;
[0051] Figure 7 This is a flowchart illustrating the process of determining the soil thermal resistance parameters of a cable micro-element in one embodiment.
[0052] Figure 8 This is a structural block diagram of a cable current carrying estimation device in one embodiment;
[0053] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation
[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0055] In one embodiment, such as Figure 1 As shown, a cable current-carrying capacity estimation method is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and to a system including both a terminal and a server, and implemented through interaction between the terminal and the server. In this embodiment, the method includes the following steps S102 to S110. Wherein:
[0056] Step S102: Obtain soil stratification parameters and a quasi-three-dimensional thermal circuit model for directional drilling cable laying.
[0057] Among them, soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions; for example, the types of soil regions include deep soil regions, shallow soil regions, the average thermal conductivity of deep soil regions, and the average thermal conductivity of shallow soil regions.
[0058] The quasi-three-dimensional thermal path model includes the cable element length, the radial heat transfer path from the cable element itself to the environmental boundary, and the axial heat transfer path of the cable element, such as... Figure 2 As shown, Region 1 represents the radial heat transfer path, and Region 2 represents the axial heat transfer path. The radial heat transfer path describes the dissipation of heat from the heat source (conductor) to the surrounding environment; the path is "from the inside out." The axial heat transfer path describes the longitudinal conduction of heat from the high-temperature section to the low-temperature section due to temperature differences at different locations on the cable; the path is "along the cable direction." In cases of deep burial and long-distance laying, directional drilling makes heat dissipation difficult in the middle section of the cable, causing the temperature to rise. Heat will be conducted to the lower-temperature areas at both ends, so it is necessary to consider the axial heat transfer path in addition to the radial heat transfer path. The quasi-three-dimensional thermal path model refers to the 2D radial heat transfer path and the 1D axial heat transfer path. Region 2 has a greater depth than Region 1, and the side of Region 1 furthest from Region 2 is the environmental boundary. The cable element length refers to the distance between two adjacent circles in Region 2.
[0059] Optionally, the terminal acquires the average thermal conductivity of the deep soil region, the shallow soil region, the average thermal conductivity of the deep soil region, and the average thermal conductivity of the shallow soil region. The terminal acquires a quasi-three-dimensional thermal path model, which includes the cable element length, radial heat transfer path, and axial heat transfer path.
[0060] Step S104: Based on the cable element length and axial heat transfer path, determine the axial thermal resistance parameter of each cable element; based on the cable element length and radial heat transfer path, determine the heat source parameter of each cable element and the radial thermal resistance parameter corresponding to each layer of the cable body to the pipe structure of each cable element.
[0061] Among them, the heat source parameter represents the rate at which heat is continuously generated within a single cable micro-element due to power loss under steady-state operating conditions.
[0062] Since the length of the cable element is known, the number of cable elements can be determined given the known cable length.
[0063] Optionally, the terminal determines the axial thermal resistance parameter of each cable element based on the cable element length and axial heat transfer path. The terminal also determines the heat source parameters of each cable element based on the cable element length and radial heat transfer path, and further determines the radial thermal resistance parameters corresponding to each layer of the cable body and conduit structure for each cable element based on the cable element length and radial heat transfer path.
[0064] Step S106: For each cable micro-element, obtain the type of the soil region to which the cable micro-element belongs; based on the average thermal conductivity corresponding to the type of soil region, determine the soil thermal resistance parameter of the cable micro-element.
[0065] Optionally, for each cable micro-element, the terminal obtains the type of the soil region to which the cable micro-element belongs; based on the average thermal conductivity corresponding to the type of soil region, the soil thermal resistance parameter of the cable micro-element is determined.
[0066] Step S108: Based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to each layer of the cable body to the pipeline structure of the same cable micro-element, determine the temperature distribution of the cable micro-element.
[0067] Optionally, the terminal determines the total radial thermal resistance parameter of the cable micro-element based on the radial thermal resistance parameters of the cable body to each layer of the duct structure corresponding to the same cable micro-element and the soil thermal resistance parameters; combines the total radial thermal resistance parameter of each cable micro-element with the heat source parameters and axial thermal resistance parameters to determine the thermal balance equation of each cable micro-element; and constructs a set of thermal circuit equations by simultaneously solving the thermal circuit equations of all cable micro-elements to determine the temperature distribution of the cable micro-element. For example, if there are 10 cable micro-elements, the thermal balance equations of the 10 cable micro-elements are simultaneously solved to obtain the conductor temperature of each cable micro-element; the conductor temperature of each cable micro-element determines the temperature distribution of the cable micro-element.
[0068] Step S110: If the temperature distribution meets the preset temperature, the current with the temperature distribution meeting the preset temperature is determined as the current carrying capacity.
[0069] Optionally, if the temperature distribution meets a preset temperature requirement, the terminal determines the current carrying capacity based on the current at which the temperature distribution meets the preset temperature requirement. For example, when the highest conductor temperature is ≤90℃ (XLPE long-term operating temperature), the corresponding current is the current carrying capacity. When the highest temperature is close to 90℃, the current is approximately 280A, so the assessed current carrying capacity of the directional drilling cable at this time is approximately 280A.
[0070] The aforementioned cable current-carrying capacity estimation method proposes a quasi-three-dimensional thermal path model based on measured soil stratification parameters and incorporating radial and axial heat transfer paths. This model comprehensively considers the influence of soil stratification and underground isothermal layers, focusing on the impact of soil stratification (differences in thermal conductivity at different soil depths) on heat transfer under conditions of large burial depth and large span. Based on the soil stratification parameters and the quasi-three-dimensional thermal path model, the thermal resistance parameters of each cable layer structure, pipe, and filling material, as well as the thermal resistance parameters of the soil, are calculated. The current-carrying capacity is then determined based on these thermal resistance parameters. This method addresses the issue that traditional techniques treat soil as a semi-infinite, homogeneous medium, resulting in insufficient accuracy for directional drilling cable laying scenarios. Ultimately, this improves the accuracy of current-carrying capacity calculations for directional drilling cables, thereby enhancing the safety and stability of power grid operation.
[0071] In one exemplary embodiment, such as Figure 3As shown, the soil regions include shallow soil regions and deep soil regions; obtaining soil stratification parameters includes steps S302 to S306. Wherein:
[0072] Step S302: Obtain soil samples at different soil depths in the cable laying area; calculate the thermal conductivity of each soil sample.
[0073] Optionally, the terminal acquires soil samples at different soil depths in the cable laying area, taking the soil at a depth x (m) below the surface as the first sampling starting point, and then collecting soil samples at different depths with a step size of x. The soil thermal resistance parameter is tested using a soil thermal resistance tester, all the way to the burial depth of the horizontal cable section, and the thermal conductivity of the soil at different depths is calculated using the steady-state plate method of formula (1). The value of the step size x is defined according to the required calculation accuracy and calculation speed. The larger the value of x, the higher the calculation accuracy, but the longer the calculation time. For example, the value of x is 0.5m.
[0074] Formula (1)
[0075] In the formula, F represents the amount of heat passing through a certain cross section per unit time, i.e., heat flow, in W; Represents thermal conductivity, measured in W / mK; This represents the temperature difference between the top and bottom sides corresponding to the thickness of the soil sample, in K. A represents the thickness of the soil sample, in meters; A represents the cross-sectional area of the soil sample, in meters.
[0076] In formula (1) The thermal conductivity of the soil sample is unknown, while all other parameters are known. Using these known parameters, the thermal conductivity of each soil sample can be obtained. .
[0077] Step S304: Determine the soil depth corresponding to the maximum difference in thermal conductivity between adjacent soils as the critical point, and divide the soil region into shallow soil region and deep soil region according to the critical point.
[0078] Optionally, the terminal calculates the difference between adjacent soil samples, obtains the maximum difference from all differences, and determines the soil depth corresponding to the maximum difference as the critical point. For example, the soil depth is 3 meters. The soil area above the critical point is divided into shallow soil area a1; the soil area below the critical point is divided into deep soil area a2, such as... Figure 4 As shown.
[0079] Step S306: Calculate the mean thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region.
[0080] Optionally, the terminal calculates the average thermal conductivity of the shallow soil region using formula (2), based on the ratio of the sum of the thermal conductivity of the shallow soil regions to the number of layers in the shallow soil region. .
[0081] The terminal calculates the average thermal conductivity of the deep soil region using formula (2), based on the ratio of the sum of the thermal conductivity of the deep soil regions to the number of layers in the deep soil region. .
[0082] It should be noted that the number of shallow soil strata and the number of deep soil strata are the same as the number of soil samples belonging to this type.
[0083] Formula (2)
[0084] In this embodiment, by calculating different types of soil stratification parameters, the effect of different soil depths on current carrying capacity estimation is clarified, and the average thermal conductivity of deep soil regions is considered in order to improve the accuracy of current carrying capacity estimation in the future.
[0085] In one exemplary embodiment, the method for determining the length of a cable micro-element includes: obtaining the total length of the directional drilling cable; dividing the directional drilling cable into a target number of cable micro-elements according to the axial direction of the directional drilling cable; and determining the length of the cable micro-element based on the total cable length and the target number.
[0086] Optionally, the terminal considers the temperature difference characteristics of different sections of the directional drilling cable, along the cable axis (e.g., Figure 2 Region 2) Divide the axial length as The isothermal cable element is used as an example. The radial heat transfer path from the cable element to the environmental boundary is constructed using the law of conservation of energy. Figure 2 As shown in Region 1, the soil thermal resistance is characterized by series soil thermal resistance because the soil thermal conductivity varies in different regions.
[0087] Optionally, the terminal obtains the total cable length L of the directional drilling cable; according to the axial direction of the directional drilling cable, the directional drilling cable is divided into a target number of n cable micro-elements; the length of the cable micro-elements is determined based on the total cable length and the target number using formula (3). .
[0088] Formula (3)
[0089] In this embodiment, by dividing the directional drilling cable into cable micro-elements of equal length, it is easier to accurately calculate the radial and axial thermal resistance parameters of the cable micro-elements, thereby improving the accuracy of subsequent current-carrying estimation.
[0090] In an exemplary embodiment, the axial thermal resistance parameter of each cable element is determined based on the cable element length and the axial heat transfer path, including: obtaining the conductor equivalent axial thermal conductivity and conductor cross-sectional area of the cable element in the axial heat transfer path; and determining the axial thermal resistance parameter of each cable element based on the conductor equivalent axial thermal conductivity, cross-sectional area, and cable element length.
[0091] Optionally, considering the temperature difference between adjacent isothermal elements, and combining thermoelectric analogy theory, the thermal behavior between each element is characterized by axial thermal resistance, forming the axial heat transfer path of the cable element as follows: Figure 2 As shown in region 2, the equivalent axial thermal conductivity of the conductor of the cable element in the axial heat transfer path is obtained at the terminal. And the cross-sectional area of the conductor; since the conductor is cylindrical in shape, its cross-section is circular, therefore the cross-sectional area of the conductor is... The terminal is based on the equivalent axial thermal conductivity of the conductor. Cross-sectional area and cable element length The axial thermal resistance parameters of each cable element are determined as shown in formula (4).
[0092] Formula (4)
[0093] In the formula, Represents the axial thermal resistance parameter of each cable element; i is the index.
[0094] In this embodiment, the axial thermal resistance parameters of each cable element can be calculated in detail by using the cable element length and axial heat transfer path.
[0095] In one exemplary embodiment, such as Figure 5 As shown, the radial heat transfer path includes a conductor, an insulation layer, and a conduit from the inside out; the radial thermal resistance parameters include the conductor thermal resistance parameter, the insulation layer thermal resistance parameter, the conduit thermal resistance parameter, and the filling material thermal resistance parameter; based on the cable element length and the radial heat transfer path, the heat source parameters of each cable element and the radial thermal resistance parameters corresponding to each layer of the cable body to the conduit structure of each cable element are determined, including steps S502 to S510. Wherein:
[0096] Step S502: Based on the conductor parameters, insulation layer structural parameters, and actual load parameters of the cable during operation, determine the conductor loss and insulation layer loss.
[0097] Optionally, the terminal uses the structural parameters of the cable conductor and insulation layer (including the diameter and axial length of each layer in the radial direction), thermal properties and electrical performance parameters, combined with the load parameters (load current value and operating frequency) of the cable during actual operation, to calculate the heat source parameters of the cable micro-element.
[0098] Optionally, the terminal is based on conductor parameters, such as the conductor's operating temperature (in °C), the temperature coefficient of the insulation layer (e.g., the temperature coefficient of cross-linked polyethylene at 20 °C), and the load parameters of the cable during actual operation, such as conductor parameters (e.g., the load current of a single-phase conductor in A), and the DC resistance of a single-phase conductor at 20 °C (in A). Substitute into formula (5) to determine the conductor loss. .
[0099] Formula (5)
[0100] In the formula, θc represents the operating temperature of the conductor; α20 represents the temperature coefficient of cross-linked polyethylene at 20℃; I represents the load current of the single-phase conductor; and R0 represents the DC resistance of the single-phase conductor at 20℃.
[0101] Optionally, the terminal determines the insulation loss based on conductor parameters such as conductor diameter, insulation structural parameters such as insulation loss factor under power system and operating temperature, dielectric constant of insulation material, and outer diameter of single-phase insulation layer; and load parameters of the cable during actual operation, such as power frequency; and voltage to ground (phase voltage), by substituting these parameters into formula (6). .
[0102] Formula (6)
[0103] In the formula, U0 represents the power supply frequency, in rad / s; U0 represents the voltage to ground (phase voltage), in V. This indicates the insulation loss factor under power system and operating temperature conditions. D represents the dielectric constant of the insulating material, taken as 2.5; i This indicates the outer diameter of a single-phase insulation layer, in mm; d c This indicates the diameter of the conductor, in mm.
[0104] Step S504: Determine the heat source parameters of the cable element based on conductor loss, insulation loss, and cable element length.
[0105] Optionally, the terminal will reduce the conductor loss Q. c and insulation layer loss Q d After adding them together, multiply by the length of the cable element to determine the heat source parameters of the cable element. .like .
[0106] Among them, conductor loss Q c and insulation layer loss Q d The unit is W / m; heat source parameters The unit is W.
[0107] Step S506: Determine the thermal resistance parameters of the conductor based on the inner and outer diameters of the conductor and the thermal conductivity of the conductor material.
[0108] Since the conductor, insulation layer and pipe are all cylinders, when the terminal calculates the thermal resistance parameters of the conductor, the terminal obtains the inner diameter and outer diameter of the conductor and the thermal conductivity of the conductor material, and determines the thermal resistance parameters of the conductor by formula (7).
[0109] Formula (7)
[0110] In the formula, The radial thermal resistance parameters representing each layer of the structure are used in the calculation of conductor thermal resistance parameters. This refers to the thermal resistance parameter of the conductor; The thermal conductivity refers to the material thermal conductivity of the cylindrical wall structure (in this case, the thermal conductivity of the straight conductor material); D and d are the outer diameter and inner diameter of the cylindrical wall structure, respectively (in this case, the outer diameter refers to the outer diameter of the conductor, and the inner diameter refers to the inner diameter of the conductor).
[0111] Step S508: Determine the thermal resistance parameters of the insulating layer based on the inner and outer diameters of the insulating layer and the thermal conductivity of the insulating layer material.
[0112] Optionally, given the thermal resistance parameters of the insulation layer, the thermal resistance parameters of the insulation layer are determined by substituting the inner and outer diameters of the insulation layer and the thermal conductivity of the insulation layer material into formula (7). In this case, formula (7)... This represents the thermal resistance parameter of the insulation layer; This refers to the thermal conductivity of the insulating layer material; D and d are the outer diameter and inner diameter of the insulating layer, respectively.
[0113] Step S510: Determine the thermal resistance parameters of the filling material based on the inner diameter of the pipe, the outer diameter of the insulation layer, and the thermal conductivity of the filling material.
[0114] Optionally, the terminal uses the shape factor method to calculate the thermal resistance parameters of the filling material based on the inner diameter of the pipe, the outer diameter of the insulation layer, and the thermal conductivity of the filling material. The shape factor method is a commonly used method for calculating thermal resistance in cable laying scenarios where eccentric circular structures exist, such as... Figure 6 As shown, the thermal resistance between the two circles of the eccentric circular structure can be calculated using formula (8), which is shown below.
[0115] Formula (8)
[0116] in, R is the thermal conductivity of the medium between the two circles in the eccentric circular structure; T represents the thermal resistance parameter of the filling material; R1 and R2 are the radii of the two eccentric circles, R1 represents the radius of the inner layer of the pipe, and R2 represents the radius of the outer layer of the insulation layer; E represents the eccentricity, that is, the distance between the centers of the two circles, with the same unit as the radius.
[0117] In this embodiment, the heat source parameters and radial thermal resistance parameters of each cable micro-element are determined by the radial heat transfer path from the inside out through the conductor, insulation layer and pipe, which enables accurate calculation of the heat source parameters and radial thermal resistance parameters of each cable micro-element.
[0118] In one exemplary embodiment, such as Figure 7 As shown, the type of soil region to which the cable micro-element belongs is obtained; based on the average thermal conductivity corresponding to the type of soil region, the soil thermal resistance parameters of the cable micro-element are determined, including steps S702 to S706. Wherein:
[0119] Step S702: Obtain the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary. If the distance is less than or equal to the thickness of the deep soil region, the type of soil region to which the cable micro-element belongs is the deep soil region. Use the average thermal conductivity of the deep soil region as the first equivalent soil thermal conductivity. Based on the first equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, determine the soil thermal resistance parameters of the cable micro-element.
[0120] The isothermal boundary refers to an imaginary boundary layer located below the soil depth where the cable is laid, where the temperature does not change over time (or the annual variation is negligible) and is unaffected by the cable's own heating. For example... Figure 4 The isothermal boundary is shown in the figure.
[0121] Pipes Figure 4 Two solid lines running through different soil layers, with the center of the pipe as... Figure 4 The dashed line between the two solid lines indicates that the distance from the center of the pipe to the constant temperature boundary is the vertical distance from the center of the pipe to the constant temperature boundary.
[0122] Optionally, the terminal obtains the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary. Furthermore, the distance and the thickness of the deep soil region were compared. When the distance was less than or equal to the thickness of the deep soil region, it indicated that the cable micro-element was the center of the circle. The heat transfer path of the cable, with a radius of [radius value], only includes deep soil, and the soil region to which the cable micro-element belongs is entirely deep soil. Therefore, the average thermal conductivity of the deep soil region is [value]. As the first equivalent soil thermal conductivity The terminal utilizes the soil thermal conductivity corresponding to the cable micro-element and combines it with the cylindrical wall structure thermal resistance calculation method provided by the IEC standard to obtain the soil thermal resistance parameters corresponding to the cable micro-element: Based on the first equivalent soil thermal conductivity, distance and outer radius of the pipe, the soil thermal resistance parameters of the cable micro-element are determined by substituting them into formula (9).
[0123] Formula (9)
[0124] In the formula, Represents soil thermal resistance parameter, first equivalent soil thermal conductivity. ,at this time The value of is the first equivalent soil thermal conductivity. The value of r; r represents the outer radius of the directional drilling pipe. This represents the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary.
[0125] Step S704: When the distance is greater than the thickness of the deep soil region and less than or equal to half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the type of soil region to which the cable micro-element belongs is a deep soil region and a shallow soil layer; based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region, a second equivalent soil thermal conductivity is determined; based on the second equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, the soil thermal resistance parameter of the cable micro-element is determined.
[0126] When the distance is greater than the thickness of the deep soil region but less than or equal to half the sum of the thicknesses of the deep and shallow soil regions, i.e., a2 <= d <= (a1 + a2) / 2, it indicates that the type of soil region to which the cable micro-element belongs includes both the deep and shallow soil layers. In other words, with the cable micro-element as the center... The heat transfer path of the cable with a radius includes only the deep soil region and the shallow soil layer. At this point, the terminal determines the second equivalent soil thermal conductivity using formula (10), based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region. .
[0127] Formula (10)
[0128] In the formula, Represented by a cable micro-element as the center, The length of the propagation path with radius in the shallow soil region can also be called the chord length of the shallow soil region. Represented by a cable micro-element as the center, The length of the propagation path with radius traversing the deep soil region can also be called the chord length of the deep soil region; The thermal conductivity of the shallow soil layer is uniform; This represents the average thermal conductivity of the deep soil region.
[0129] Step S706: When the distance is greater than half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the type of soil region to which the cable micro-element belongs is a deep soil region and a shallow soil layer; based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region, a second equivalent soil thermal conductivity is determined; based on the second equivalent soil thermal conductivity, the outer radius of the pipe, the thickness of the deep soil region and the thickness of the shallow soil region, the soil thermal resistance parameter of the cable micro-element is determined.
[0130] Optionally, if the distance is greater than half the sum of the thicknesses of the deep soil region and the shallow soil region, i.e., d > (a1 + a2) / 2, it indicates that the type of soil region to which the cable micro-element belongs includes both the deep soil region and the shallow soil layer, that is, with the cable micro-element as the center, The heat transfer path of the cable with a radius includes only the deep soil region and the shallow soil layer. At this point, the terminal determines the second equivalent soil thermal conductivity using formula (10), based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region. The terminal utilizes the soil thermal conductivity corresponding to the cable micro-element. Based on the position of the cable micro-element in the soil domain, the soil thermal resistance parameters corresponding to the cable micro-element are calculated using the shape factor method, including: determining the soil thermal resistance parameters of the cable micro-element based on the second equivalent soil thermal conductivity, the outer radius of the pipe, the thickness of the deep soil region and the thickness of the shallow soil region, as shown in formula (11).
[0131] Formula (11)
[0132] In the formula, Represents soil thermal resistance parameters. Represents the second equivalent soil thermal conductivity. a1 represents the outer radius of the pipe, a2 represents the thickness of the shallow soil region, and a1 represents the thickness of the deep soil region. This represents the difference between the outer radius of the circle centered on the cable element and with a radius of (a1+a2) / 2 and the outer radius of the pipe.
[0133] In this embodiment, based on the cable micro-element as the center, The heat transfer path of the cable with radius includes different types of soil regions. Different methods for calculating soil thermal conductivity and soil thermal resistance parameters have been determined to meet the accuracy requirements of cable directional drilling and laying scenarios. This overcomes the problem of poor accuracy caused by treating the soil as a semi-infinite or homogeneous medium in traditional technologies.
[0134] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.
[0135] Based on the same inventive concept, this application also provides a cable current carrying capacity estimation device for implementing the cable current carrying capacity estimation method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more cable current carrying capacity estimation device embodiments provided below can be found in the limitations of the cable current carrying capacity estimation method described above, and will not be repeated here.
[0136] In one exemplary embodiment, such as Figure 8 As shown, a cable current-carrying estimation device is provided, comprising: an acquisition module 801, a first determination module 802, a second determination module 803, a third determination module 804, and a current-carrying estimation module 805, wherein:
[0137] The acquisition module 801 is used to acquire soil stratification parameters and a quasi-three-dimensional thermal path model of the directional drilling cable. The soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions. The quasi-three-dimensional thermal path model includes the cable element length, the radial heat transfer path from the cable body of the cable element to the environmental boundary, and the axial heat transfer path of the cable element.
[0138] The first determining module 802 is used to determine the axial thermal resistance parameter of each cable micro-element based on the cable micro-element length and axial heat transfer path; and to determine the heat source parameter of each cable micro-element and the radial thermal resistance parameter of each layer of the cable body to the pipe structure of each cable micro-element based on the cable micro-element length and radial heat transfer path.
[0139] The second determining module 803 is used to obtain the type of soil region to which each cable micro-element belongs; and to determine the soil thermal resistance parameter of the cable micro-element based on the average thermal conductivity corresponding to the type of soil region.
[0140] The third determining module 804 is used to determine the temperature distribution of the cable micro-element based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to the cable body to each layer of the pipeline structure of the same cable micro-element.
[0141] The current carrying capacity is determined by the current when the temperature distribution meets the preset temperature.
[0142] In an exemplary embodiment, the acquisition module 801 is further configured to acquire soil samples at different soil depths in the cable laying area; calculate the thermal conductivity of each soil sample; determine the soil depth corresponding to the maximum difference between adjacent thermal conductivity as a critical point, and divide the soil area into shallow soil area and deep soil area according to the critical point; and calculate the average thermal conductivity of the shallow soil area and the average thermal conductivity of the deep soil area.
[0143] In one exemplary embodiment, a cable current carrying capacity estimation device further includes a cable micro-element length determination module, used to obtain the total length of the directional drilling cable; divide the directional drilling cable into a target number of cable micro-elements according to the axial direction of the directional drilling cable; and determine the length of the cable micro-elements based on the total cable length and the target number.
[0144] In an exemplary embodiment, the first determining module 802 is further configured to obtain the conductor equivalent axial thermal conductivity and conductor cross-sectional area of the cable micro-element in the axial heat transfer path; and determine the axial thermal resistance parameter of each cable micro-element based on the conductor equivalent axial thermal conductivity, cross-sectional area and cable micro-element length.
[0145] In an exemplary embodiment, the radial heat transfer path includes a conductor, an insulation layer, and a conduit from the inside out; the radial thermal resistance parameters include conductor thermal resistance parameters, insulation layer thermal resistance parameters, conduit thermal resistance parameters, and filler material thermal resistance parameters; the first determining module 802 is further configured to determine conductor loss and insulation layer loss based on conductor parameters, insulation layer structural parameters, and actual load parameters during cable operation; determine heat source parameters of the cable micro-element based on conductor loss, insulation layer loss, and cable micro-element length; determine conductor thermal resistance parameters based on the inner and outer diameters of the conductor and the thermal conductivity of the conductor material; determine insulation layer thermal resistance parameters based on the inner and outer diameters of the insulation layer and the thermal conductivity of the insulation layer material; and determine filler material thermal resistance parameters based on the inner diameter of the conduit, the outer diameter of the insulation layer, and the thermal conductivity of the filler material material.
[0146] In an exemplary embodiment, the second determining module 803 is further configured to obtain the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary; if the distance is less than or equal to the thickness of the deep soil region, the soil region to which the cable micro-element belongs is a deep soil region; the average thermal conductivity of the deep soil region is used as the first equivalent soil thermal conductivity; based on the first equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, the soil thermal resistance parameter of the cable micro-element is determined; if the distance is greater than the thickness of the deep soil region but less than or equal to half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the soil region to which the cable micro-element belongs is a deep soil region and a shallow soil layer; based on the shallow soil layer... The average thermal conductivity of the soil region and the average thermal conductivity of the deep soil region are used to determine the second equivalent soil thermal conductivity. Based on the second equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, the soil thermal resistance parameters of the cable micro-element are determined. When the distance is greater than half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the soil region to which the cable micro-element belongs is classified as either a deep soil region or a shallow soil layer. Based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region, the second equivalent soil thermal conductivity is determined. Based on the second equivalent soil thermal conductivity, the outer radius of the pipe, the thickness of the deep soil region, and the thickness of the shallow soil region, the soil thermal resistance parameters of the cable micro-element are determined.
[0147] Each module in the aforementioned cable current carrying capacity estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.
[0148] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 9As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores cable data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When executed by the processor, the computer program implements a cable current-carrying estimation method.
[0149] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0150] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.
[0151] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.
[0152] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.
[0153] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.
[0154] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.
[0155] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A method for estimating the current carrying capacity of a cable, characterized in that, The method includes: Obtain soil stratification parameters and a quasi-three-dimensional thermal path model for directional drilling cable laying; wherein, the soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions; the quasi-three-dimensional thermal path model includes the cable element length, the radial heat transfer path from the cable body of the cable element to the environmental boundary, and the axial heat transfer path of the cable element. Based on the length of the cable element and the axial heat transfer path, the axial thermal resistance parameter of each cable element is determined; based on the length of the cable element and the radial heat transfer path, the heat source parameter of each cable element and the radial thermal resistance parameter corresponding to each layer of the cable body to the pipe structure of each cable element are determined. For each cable micro-element, the type of the soil region to which the cable micro-element belongs is obtained; based on the average thermal conductivity corresponding to the type of soil region, the soil thermal resistance parameter of the cable micro-element is determined. The temperature distribution of the cable micro-element is determined based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to each layer of the cable body to the pipeline structure of the same cable micro-element. When the temperature distribution meets the preset temperature, the current that meets the preset temperature is determined as the current carrying capacity.
2. The method according to claim 1, characterized in that, The soil regions are classified into shallow soil regions and deep soil regions; the acquisition of soil stratification parameters includes: Soil samples were obtained at different depths in the cable laying area; Calculate the thermal conductivity of each of the soil samples; The soil depth corresponding to the maximum difference in thermal conductivity between adjacent soils is determined as the critical point, and the soil region is divided into shallow soil region and deep soil region according to the critical point. Calculate the mean thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region.
3. The method according to claim 1, characterized in that, The method for determining the length of the cable element includes: Obtain the total length of the directional drilling cable; According to the axial direction of the directional drilling cable, the directional drilling cable is divided into a target number of cable micro-elements; The length of a cable element is determined based on the total length of the cable and the target quantity.
4. The method according to claim 1, characterized in that, The determination of the axial thermal resistance parameter of each cable element based on the cable element length and the axial heat transfer path includes: Obtain the equivalent axial thermal conductivity and cross-sectional area of the conductor of the cable element in the axial heat transfer path; Based on the conductor's equivalent axial thermal conductivity, the cross-sectional area, and the cable element length, the axial thermal resistance parameter of each cable element is determined.
5. The method according to claim 1, characterized in that, The radial heat transfer path includes a conductor, an insulation layer, and a conduit from the inside out; the radial thermal resistance parameters include conductor thermal resistance parameters, insulation layer thermal resistance parameters, conduit thermal resistance parameters, and filling material thermal resistance parameters; determining the heat source parameters of each cable micro-element and the radial thermal resistance parameters corresponding to each layer of the cable body to the conduit structure of each cable micro-element based on the cable micro-element length and the radial heat transfer path includes: Based on the conductor parameters, the insulation layer structural parameters, and the load parameters of the cable during actual operation, the conductor loss and insulation layer loss are determined. Based on the conductor loss, the insulation layer loss, and the cable element length, determine the heat source parameters of the cable element; The thermal resistance parameters of the conductor are determined based on the inner and outer diameters of the conductor and the thermal conductivity of the conductor material. Based on the inner and outer diameters of the insulating layer and the thermal conductivity of the insulating layer material, the thermal resistance parameters of the insulating layer are determined. The thermal resistance parameters of the filling material are determined based on the inner diameter of the pipe, the outer diameter of the insulation layer, and the thermal conductivity of the filling material.
6. The method according to claim 1, characterized in that, The step of obtaining the type of soil region to which the cable micro-element belongs; and the step of determining the soil thermal resistance parameter of the cable micro-element based on the average thermal conductivity corresponding to the type of soil region, includes: Obtain the distance from the center of the pipe corresponding to the cable micro-element to the constant temperature boundary. If the distance is less than or equal to the thickness of the deep soil region, the soil region to which the cable micro-element belongs is a deep soil region. Use the average thermal conductivity of the deep soil region as the first equivalent soil thermal conductivity. Based on the first equivalent soil thermal conductivity, the distance, and the outer radius of the pipe, determine the soil thermal resistance parameter of the cable micro-element. When the distance is greater than the thickness of the deep soil region but less than or equal to half the sum of the thicknesses of the deep soil region and the shallow soil region, the soil region to which the cable micro-element belongs is classified as either a deep soil region or a shallow soil layer. A second equivalent soil thermal conductivity is determined based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region. The soil thermal resistance parameter of the cable micro-element is determined based on the second equivalent soil thermal conductivity, the distance, and the outer radius of the pipe. When the distance is greater than half the sum of the thickness of the deep soil region and the thickness of the shallow soil region, the type of soil region to which the cable micro-element belongs is a deep soil region and a shallow soil layer; a second equivalent soil thermal conductivity is determined based on the average thermal conductivity of the shallow soil region and the average thermal conductivity of the deep soil region; the soil thermal resistance parameter of the cable micro-element is determined based on the second equivalent soil thermal conductivity, the outer radius of the pipe, the thickness of the deep soil region and the thickness of the shallow soil region.
7. A cable current-carrying estimation device, characterized in that, The device includes: The acquisition module is used to acquire soil stratification parameters and a quasi-three-dimensional thermal path model of directional drilling cable laying; wherein, the soil stratification parameters include the type of soil region and the average thermal conductivity of different types of soil regions; the quasi-three-dimensional thermal path model includes the cable micro-element length, the radial heat transfer path from the cable body of the cable micro-element to the environmental boundary, and the axial heat transfer path of the cable micro-element. The first determining module is used to determine the axial thermal resistance parameter of each cable micro-element based on the length of the cable micro-element and the axial heat transfer path; and to determine the heat source parameter of each cable micro-element and the radial thermal resistance parameter corresponding to each layer of the cable body to the pipe structure of each cable micro-element based on the length of the cable micro-element and the radial heat transfer path. The second determining module is used to obtain the type of soil region to which each cable micro-element belongs; and to determine the soil thermal resistance parameter of the cable micro-element based on the average thermal conductivity corresponding to the type of soil region. The third determining module is used to determine the temperature distribution of the cable micro-element based on the radial thermal resistance parameters, soil thermal resistance parameters, heat source parameters, and axial thermal resistance parameters corresponding to the cable body to each layer of the pipeline structure of the same cable micro-element. The current carrying capacity is determined by the current at which the temperature distribution satisfies the preset temperature, provided that the temperature distribution satisfies the preset temperature.
8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.
9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.
10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.