Deeply buried pipeline early warning detection device and detection method

Abstract

The invention discloses a deep buried pipeline early warning detection device and a detection method in the field of deep buried pipeline detection. The early warning detection device comprises a pull wire; the detection coil group comprises at least three detection coils which are mounted at the bottom of the pull wire at equal intervals from top to bottom; the vertical fixed shaft is fixedly connected with each detection coil; the induced electromotive force testing device is respectively connected with the detection coils through wires; wherein the detection coil comprises a magnetic core and a winding wire, the magnetic core is in a circular ring shape, the winding wire is arranged in the circumferential direction of the magnetic core in a symmetrical winding mode, coils formed by the winding wire are distributed in a mirror symmetry mode, and the starting point and the end point of the winding wire are connected with the induced electromotive force measuring device. The early-warning detection device for the deeply-buried pipeline can accurately position a target pipeline below (including right below) a coil, and plays a role in forecasting in the implementation process of a test hole; and the detection coil of the early warning detection device can improve the accuracy of detection data so as to further realize accurate positioning.

Description

Technical Field

[0001] The present invention relates to the technical field of deep-buried pipeline detection, and in particular to a deep-buried pipeline early warning detection device and a detection method. Background Art

[0002] During the special detection process of deep-buried pipelines, test holes are generally arranged at a certain distance perpendicular to the direction of the target pipeline with the survey pipeline positioning point. Due to the poor surface positioning accuracy of the deep-buried pipeline survey, there is a great risk that the water drill bit will touch the target during the implementation of the first test hole. For example, for the West-East Gas Pipeline, the water drill bit will most likely damage the pipeline's anti-corrosion layer after touching the target pipeline. After the anti-corrosion layer is damaged, the pipeline life will drop sharply, resulting in great economic losses and social impacts. Currently, there is no good method to predict and forecast whether the target pipeline is distributed within a certain depth range below the water drill bit during the test hole drilling process.

[0003] Furthermore, conventional visual verification, typically performed as the final step in pipeline inspections, is limited by the on-site environment. Factors such as the presence of heavy debris and hard soil covering the pipeline, turbid flushing water, collapsed or shrinkage holes, and other factors can prevent the test casing from reaching the top of the pipeline, or the color difference between the pipeline and the surrounding soil is minimal. These factors can result in blurry visual camera footage, making it impossible to determine whether the bottom of the casing is the target pipeline. When visual verification struggles to identify the target pipeline, there is currently no practical method to determine whether the target pipeline is located within a certain depth range from the casing bottom. Summary of the Invention

[0004] This application solves the problem in the prior art that it is impossible to predict the implementation of the test hole and accurately locate the target pipeline below the coil by providing a deep-buried pipeline early warning detection device and detection method. It realizes the accurate positioning of the target pipeline below the test hole and the prediction work during the implementation of the test hole, greatly reduces the risk probability of damage to the pipeline during special detection work, and improves the detection efficiency.

[0005] The present invention provides a deep-buried pipeline early warning detection device, comprising:

[0006] traction line;

[0007] A detection coil assembly, comprising at least three detection coils, the detection coils being installed at equal intervals from top to bottom at the bottom of the traction line;

[0008] A vertical fixed shaft, fixedly connected to each of the detection coils, for keeping the central axes of the detection coils collinear;

[0009] an induced electromotive force testing device, connected to each of the detection coils via a wire;

[0010] Among them, the detection coil includes a magnetic core and a winding wire. The magnetic core is annular. The winding wire is arranged along the circumference of the magnetic core in a symmetrical winding manner. The coils formed by the winding wire are distributed in a mirror-symmetrical manner. The starting point and end point of the winding wire are respectively connected to the induced electromotive force measuring device.

[0011] The beneficial effects of the above embodiment are: the deep-buried pipeline early warning detection device can accurately locate the target pipeline below (including directly below) the coil through the induced electromotive force of at least three detection coils, and play a predictive role in the implementation of the test hole; and the detection coil of the deep-buried pipeline early warning detection device can obtain the same induced electromotive force test value when rotated at any angle along the center line as the axis, thereby improving the accuracy of the detection data to further achieve precise positioning, greatly reducing the risk probability of damage to the pipeline in special detection work, and improving detection efficiency.

[0012] Based on the above embodiments, the present application can be further improved as follows:

[0013] In one embodiment of the present application, the detection device further includes an early warning device for receiving and processing the induced electromotive force data transmitted by the induced electromotive force measurement device. The early warning device's real-time data processing capabilities enable rapid determination of the target pipeline's approach status, significantly improving early warning response speed and avoiding the risk of misoperation caused by delayed manual analysis.

[0014] In one embodiment of the present application, the normal direction of the vertical cross-section of the detection coil is parallel to the tangent direction of the circular ring of the magnetic core, and the normal direction of the vertical cross-section of all the coils is perpendicular to the centerline of the magnetic core. This design ensures that the test value of the induced electromotive force of the coil remains consistent at different horizontal azimuth angles, eliminates measurement errors caused by coil rotation, and significantly improves the stability and reliability of the detection data.

[0015] In one embodiment of the present application, the spacing between adjacent windings does not exceed 3 mm. The tight winding spacing enhances the coil's magnetic field sensitivity, enabling it to capture weaker alternating current signals, thereby improving the detection accuracy of deeply buried pipelines, and is particularly suitable for target positioning in complex geological conditions.

[0016] In one embodiment of the present application, there are three detection coils. The symmetrical layout of the three detection coils, combined with the simultaneous solution of multiple sets of data, can effectively eliminate the accidental error of a single detection point and significantly improve the calculation accuracy of the horizontal distance (b) and vertical distance (h).

[0017] In one embodiment of this application, the magnetic core is made of a strong magnetic material with an outer diameter of 5 cm, an inner diameter of 3 cm, and a height of 10 cm. The center-to-center spacing a between adjacent detection coils is 15-30 cm. The optimized core size and coil spacing ensure both the miniaturization and portability of the detection device and sufficient magnetic field coverage, enabling both efficiency and accuracy in deephole detection.

[0018] The present application also provides a method for early warning detection of deep-buried pipelines, which uses the above-mentioned early warning detection device for deep-buried pipelines and includes the following steps:

[0019] S1: applying an alternating current to the target pipeline and drilling test holes in stages. During each drilling stop, the detection coil group is lowered and the induced electromotive force between different detection coils is used to determine whether the target pipeline is close. If it is determined that the target pipeline is close, the process proceeds to step S2;

[0020] S2: Obtain the induced electromotive force A, B, and C of the three detection coils from bottom to top, and obtain the horizontal distance b between the detection coil group and the target pipeline, and the vertical distance h between the detection coil group and the target pipeline. Specifically:

[0021] If 4AC-2AB-2BC=0, then b=0, and h can be solved using the following formula:

[0022] or

[0023] Wherein, a is the distance between the center points of adjacent detection coils;

[0024] If 4AC-2AB-2BC≠0, then b and h are solved using the following formulas:

[0025]

[0026]

[0027] In one embodiment of the present application, in step S1, the determination of whether the detection coil group is close to the target pipeline is specifically as follows: obtaining the induced electromotive force A, B, and C of the three detection coils from bottom to top; if the induced electromotive force of the detection coil group gradually increases and If the value is less than the set threshold, the drilling distance of each stage of the test hole is shortened and step S1 is repeated. If the value is greater than the set threshold, the target pipeline is determined to be close and the process proceeds to step S2. By dynamically adjusting the drilling distance and the threshold judgment mechanism, a progressive approach to the target pipeline is achieved, avoiding both efficiency losses caused by premature drilling stoppage and the risk of pipeline damage caused by excessive drilling.

[0028] In one embodiment of the present application, in step S2, multiple sets of data are obtained for verification by adjusting the position of the detection coil assembly up and down. Verification with multiple sets of data effectively eliminates accidental errors in a single measurement, further improving the confidence level of the positioning results and ensuring the scientific nature and repeatability of the detection results.

[0029] In one embodiment of the present application, it also includes:

[0030] Step S3: Based on the calculated vertical distance h between the detection coil assembly and the target pipeline, the test hole is drilled further down, and b and h are re-derived based on the induced electromotive forces A, B, and C. This allows for more accurate data and precise positioning. Through calculation and multiple verifications, pipeline position parameters can be dynamically corrected, ultimately achieving millimeter-level positioning accuracy, providing a reliable basis for subsequent construction.

[0031] The deep-buried pipeline early warning detection device provided in the embodiment of the present application is combined with the detection method to realize forecasting during the implementation of the test hole, accurately locate the target pipeline within the range below (including directly below) the coil, and the difference in the test data of the coil at different azimuth angles is extremely small, which greatly reduces the risk probability of damage to the pipeline during special detection work, improves detection efficiency, saves special detection implementation costs, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0033] Figure 1 This is a structural diagram of a deep-buried pipeline early warning detection device in an embodiment of the present application;

[0034] Figure 2 This is a schematic diagram of a process of winding an enameled wire of a detection coil around a magnetic core in an embodiment of the present application;

[0035] Figure 3 This is a schematic diagram of the induced electromotive force analysis of the detection coil group in the embodiment of the present application.

[0036] Among them, 1. detection coil, 2. induced electromotive force measuring device, 3. traction line, 4. vertical fixed axis, 5. early warning device. DETAILED DESCRIPTION

[0037] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the terms "vertical", "peripheral surface" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use. These are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, terms such as "vertical" do not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0040] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] In the description of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine different embodiments or examples described in the present invention, as well as features of different embodiments or examples, without any contradiction.

[0042] The embodiments of the present application provide a deep-buried pipeline early warning detection device and detection method, which solves the problem in the prior art that it is impossible to perform forecasting work during the implementation of the test hole and accurately locate the target pipeline below the coil. It realizes the accurate positioning of the target pipeline below the test hole and the forecasting work during the implementation of the test hole, greatly reduces the risk probability of damage to the pipeline during special detection work, improves detection efficiency, saves special detection implementation costs, and has significant economic and social benefits.

[0043] The technical solution in the embodiments of the present application is to solve the above problems, and the overall idea is as follows:

[0044] Example 1:

[0045] like Figure 1 As shown, a detection device includes three detection coils 1 and corresponding induced electromotive force measuring devices 2. The three detection coils 1 form a detection coil group 1 which is equidistantly installed on a traction line 3. The center line of the detection coil 1 is vertically arranged parallel to the center line of the traction line 3. The three detection coils 1 are fixed along the symmetry axis of the circle center using a vertical fixed axis 4 to ensure that the distance between the strong magnetic center points of two adjacent detection coils 1 is a and the rectangular frame formed by the vertical fixed axis 4 is located in the vertical section to ensure that the center of gravity of the coil group as a whole and the center of the circle of the three detection coils 1 are on the same vertical line. The three detection coils 1 are respectively connected to the induced electromotive force testing device on the ground through connecting lines.

[0046] The center distance a between adjacent coils is 15-30 cm.

[0047] Pull line 3: moderate thickness, with a certain degree of flexibility, to ensure that the traction line 3 always remains vertical during the coil's fall in the hole; the traction line 3 is provided with scale marks, the minimum scale unit is 1cm, which is used to accurately measure the coil's lowering depth.

[0048] The detection device also includes an early warning device 5, which can be a computer for receiving and processing the induced electromotive force data sent by the induced electromotive force measuring device 2. The early warning device 5 calculates the horizontal distance b between the center of the detection coil 1 and the center of the target pipeline, and the vertical distance h between the center of the detection coil group 1 and the center of the target pipeline based on the data.

[0049] During magnetic induction potential detection, conventional coils produce discrepancies in test data when rotated to different positions. Accurate detection data often requires the coil to be fixed in one position during actual testing. This is very difficult to maintain in one position during actual operation. Therefore, the present invention improves the detection coil.

[0050] A detection coil comprising:

[0051] The magnetic core has a circular horizontal cross section and is made of a strong magnetic material (ferromagnetic or ferrimagnetic material) with an outer diameter of 5 cm, an inner diameter of 3 cm, and a height of 10 cm;

[0052] The winding wire (enameled wire) is arranged along the circumference of the magnetic core in a symmetrical winding manner, and the winding path is continuous and uninterrupted. The starting point and end point of the winding wire are respectively connected to the induced electromotive force measuring device; the normal direction of the vertical section of each coil (the winding wire is wound around the inner and outer circles of the magnetic core as one coil) is parallel to the tangent direction of the magnetic core, and the normals of the vertical sections of all coils are perpendicular to the vertical direction (center line of the magnetic core).

[0053] The symmetrical winding method makes the coils on both sides of any diameter wire distributed in a mirror-symmetrical manner, and the distance between adjacent coils does not exceed 3mm.

[0054] The diagram of enameled wire wrapped around the magnetic core is as follows Figure 2 As shown, specifically:

[0055] Use enameled wire to wind the magnetic core. The winding node sequence is as follows: The starting point of the induced electromotive force test device is 1:

[0056] 1~2(6)~3~4~5~6(2)~7(11)~8(12)~9~10~11(7)~12(8)~13(17)~14(18)~15~16~17(13)~18(14)~19(23)~20(24)~21~22~23(19)~24(20)~25~26~…~n, node 26 continues to be wound symmetrically backward until the core is wound around once at equal intervals, and the end point is connected to the end point of the induced electromotive force test device to complete the single-layer winding of the core. Some nodes will pass through twice, such as 6(2) represents that node 6 coincides with node 2.

[0057] During the winding process, it should be ensured that the cross-sections of the two symmetrically wound coils are on the same plane, and the cross-sections of the coils are evenly distributed on the magnetic core ring. It should be ensured that the cross-section direction of the coils is vertical, the normal direction of the cross-section is the tangent direction of the ring, and the normal is perpendicular to the vertical direction. This can ensure that the vertical coil can obtain the same induced electromotive force test value when rotated at any angle along the vertical line.

[0058] The advantages of the above winding method are:

[0059] ① If only enameled wire is wound from the outer ring to the inner ring, the magnetic flux generated by the target pipeline directly below in the receiving coil is zero. The detection coil design of this embodiment avoids this problem.

[0060] ② If the circular ring is divided along any diameter line, the two sides of the diameter are wound in sequence along the outer ring to the inner ring, and then connected in parallel to the induced electromotive force test device, although the induced electromotive force can be detected, it is necessary to ensure that the diameter line is perpendicular to the detection target pipeline in order to achieve the required detection data. In theoretical design, a fixed axis can be used to rotate the coil on a plane to determine the orientation of the coil, but it is difficult to accurately control the rotation angle during actual operation, which will lead to a certain deviation in the test data. The detection coil designed in this embodiment has the same direction of the induced current in the coil no matter where it is rotated in the horizontal direction, and the induced electromotive force test data are all constant values, which reduces the difficulty of testing and the feasibility of actual operation;

[0061] ③ The induced electromotive force can be increased by increasing the coil height and the number of coil turns, making the anti-interference ability stronger in the actual process;

[0062] ④ The normal line of the circular ring cross section is parallel to the tangent line of the ring and perpendicular to the vertical direction, so that the coil can detect the pipeline directly below.

[0063] Example 2:

[0064] like Figure 3 As shown, a deep-buried pipeline early warning detection method, using the detection device shown in Example 2, includes the following steps:

[0065] S1: Apply alternating current to the target pipeline, and drill test holes in stages with a stage footage of 5m. During each stage of drilling suspension, the detection coil group is lowered and the induced electromotive force test is performed; as the coil group continues to approach the pipeline, the induced electromotive force tested by the coil group continues to increase. Considering that the diameter of conventional pipelines is generally less than 4m, that is, the test hole is located within 2m on both sides of the center of the pipeline for forecasting work, it is assumed that the induced electromotive force A, B, and C of the three detection coils are obtained from the bottom up. This induced electromotive force test device is connected to the early warning device, and the early warning device calculates the induced electromotive force test value of the coil group. If the induced electromotive force of the detection coil group gradually increases during the test, but Then the drilling distance of the test hole is shortened at each stage, and step S1 is repeated. If the induced electromotive force of the detection coil group during the test is It is determined that the target pipeline is close and the process goes to step S2;

[0066] In this step, especially during the implementation of the first test hole, drilling can be stopped every 5 meters, and the detection device can be lowered vertically along the test hole, keeping the symmetry axis of the three detection coils coincident with the hole axis; record the electromagnetic test data at a sampling interval of 5cm-10cm each time it moves down, and observe the changes in the test curve of the detection coil. When it is found that the signal of the test curve (induced electromotive force) gradually increases but does not reach the set threshold, it means that the coil group (three detection coils) is approaching the target pipeline, and the next drilling stop interval will be changed to 2-3 meters; when it is found that the signal of the test curve reaches the set threshold, it means that the coil group is very close to the target pipeline, and the next data measurement and calculation can be carried out.

[0067] S2: Obtain the induced electromotive force A, B, and C of the three detection coils (in order from bottom to top), and based on this, obtain the horizontal distance b between the center of the detection coil and the center of the target pipeline, and the vertical distance h between the center of the detection coil group and the center of the target pipeline. Specifically:

[0068] If 4AC-2AB-2BC=0, it means that the detection coil (or test hole) is located directly above the target pipeline, that is, the horizontal distance b between the detection coil group and the target pipeline is 0. The vertical distance h from the center of the detection coil group to the center of the target pipeline can be solved by the following formula:

[0069] or

[0070] Wherein, a is the distance between the strong magnetic center points of adjacent detection coils;

[0071] If 4AC-2AB-2BC≠0, it means that the detection coil (or test hole) is located obliquely above the target pipeline, that is, b≠0. Then the horizontal distance b between the detection coil group and the target pipeline and the vertical distance h from the center of the detection coil group to the center of the target pipeline can be solved by the following formula:

[0072]

[0073] It should be noted that the verification process in step S2 can be verified by adjusting the position of the detection coil up and down to obtain multiple sets of data. Based on the calculated b and h, combined with the lowering depth of the detection coil, the location of the target pipeline can be accurately calculated.

[0074] S3: Based on the calculated vertical distance h between the detection coil group and the target pipeline, the test hole is further drilled, and b and h are obtained again based on the induced electromotive force A, B, and C, in order to obtain more accurate data and ensure precise positioning.

[0075] For example, if in step S2, the detection coil is lowered to the bottom of the test hole and the vertical distance h at this time is obtained, if h is greater than 1.5+a, the test hole is drilled again with h-1 meter as the stop drilling distance. After stopping drilling, the new test data is used to solve h and b to ensure accurate positioning.

[0076] The acquisition of h and b is based on the detection coil set with a specific winding in Example 1. How to obtain h and b according to the induced electromotive force A, B, and C is further explained as follows: Figure 3 As shown:

[0077] ①Analysis of induced electromotive force of a single detection coil;

[0078] Apply an alternating current to the target pipeline, and place a single detection coil into the test hole through the traction line to ensure that the center line of the coil coincides with the vertical line. Assume that the number of turns of the coil is 2n, the coil cross section is S, u is the relative magnetic permeability of the magnetic core, u0 is the vacuum magnetic permeability, the alternating current applied to the target pipeline is I=I0 sinωt, and the angle between the normal line of each coil cross section and the magnetic induction line is θ1~θ n , the distance from the coil to the center of the target pipeline is r, the horizontal distance between the coil and the target pipeline is b, and the vertical distance between the coil and the target pipeline is h, then r 2 =h 2 +b 2 , the angle between the perpendicular line from the coil to the target pipeline and the vertical line is β, When b=0, that is, the coil is located directly above the pipeline, β=90°.

[0079] The induced electromotive force generated at any point in the test hole is:

[0080]

[0081] Because 2 =h 2 +b 2 , let (cosθ1+cosθ2+…+cosθ n ) is K, then make but:

[0082]

[0083] ②Analysis of induced electromotive force of detection coil group;

[0084] Assume that the three coils are located on the same vertical line, the distance between the center points of two adjacent coils is a constant value a, the induced electromotive force generated by the three coils located at any position diagonally above or above the target pipeline is A, B, and C from bottom to top, the vertical depths from the target pipeline are ha, h, and h+a, respectively, and the distance between the coil and the target pipeline is b. The following set of equations can be obtained.

[0085]

[0086] Among them, T, h, and b are unknowns. After eliminating T by dividing the three equations by two, we get:

[0087]

[0088] Combining the two equations, we get:

[0089]

[0090] After conversion, the following equation can be obtained:

[0091] (4AC-2AB-2BC)h 2 +aB(CA)h+a 2 B(A+C)=0 (6);

[0092] When 4AC-2AB-2BC=0, b=0, that is, the coil is located directly above the target pipeline:

[0093]

[0094] When 4AC-2AB-2BC≠0, then b≠0, that is, the coil is located diagonally above the target pipeline. At this time, h can be calculated using the root-finding formula:

[0095]

[0096] After h is obtained, the value of b can be obtained according to equation group (4):

[0097]

[0098] It can be seen that the detection coil group can accurately locate the target pipeline within a certain distance range below it and predict the work during the implementation of the test hole, and the coil test data at different azimuths are consistent. In particular, when visual verification is difficult to identify the target pipeline, after applying an alternating current to the target pipeline, the coil group can be placed at a certain depth above the bottom of the hole, and the spatial position relationship between the target pipeline and the coil group can be solved based on the measured data using formulas (7), (8), and (9). It can be seen that based on the coil with a specific winding method in Example 1, the h and b between the detection coil group and the target pipeline can be obtained more concisely and accurately.

[0099] The technical solution in the above-mentioned embodiment of the present application addresses the existing problems in the on-site implementation of pipeline special detection process. Through the derivation of formulas and theoretical research, it solves the problems in the field of pipeline special detection, such as the inability to predict the implementation process of the test hole, the accurate positioning of the target pipeline within a certain distance below the coil, and the difference in test data of the coil at different azimuths. It greatly reduces the risk probability of damage to the pipeline during special detection work, improves detection efficiency, saves the implementation cost of special detection, and has significant economic and social benefits.

[0100] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A deep buried pipeline early warning detection device, characterized in that: include: traction line; A detection coil assembly, comprising at least three detection coils, the detection coils being installed at equal intervals from top to bottom at the bottom of the traction line; A vertical fixed shaft, fixedly connected to each of the detection coils, for keeping the central axes of the detection coils collinear; an induced electromotive force testing device, connected to each of the detection coils via a wire; Among them, the detection coil includes a magnetic core and a winding wire. The magnetic core is annular. The winding wire is arranged along the circumference of the magnetic core in a symmetrical winding manner. The coils formed by the winding wire are distributed in a mirror-symmetrical manner. The starting point and end point of the winding wire are respectively connected to the induced electromotive force measuring device.

2. The deep-buried pipeline early warning detection device according to claim 1 is characterized in that: The detection device also includes an early warning device for receiving and processing the induced electromotive force data sent by the induced electromotive force measuring device.

3. The deep-buried pipeline early warning detection device according to claim 1 is characterized in that: The normal direction of the vertical cross section of the winding of the detection coil is parallel to the tangent direction of the circular ring of the magnetic core, and the normal lines of the vertical cross sections of all the windings are perpendicular to the center line of the magnetic core.

4. The deep-buried pipeline early warning detection device according to claim 3 is characterized by: The distance between adjacent coils does not exceed 3 mm.

5. The deep-buried pipeline early warning detection device according to claim 3 is characterized in that: There are three detection coils.

6. The deep-buried pipeline early warning detection device according to claim 4, characterized in that: The magnetic core is made of a strong magnetic material with an outer diameter of 5 cm, an inner diameter of 3 cm, and a height of 10 cm. The center distance a between adjacent detection coils is 15-30 cm.

7. A method for early warning detection of a deep-buried pipeline, using the deep-buried pipeline early warning detection device according to any one of claims 1 to 6, comprising the following steps: S1: applying an alternating current to the target pipeline and drilling test holes in stages. During each drilling stop, the detection coil group is lowered and the induced electromotive force between different detection coils is used to determine whether the target pipeline is close. If it is determined that the target pipeline is close, the process proceeds to step S2; S2: Obtain the induced electromotive forces A, B, and C of the three detection coils from bottom to top, and obtain the horizontal distance b between the detection coil group and the target pipeline, and the vertical distance h between the detection coil group and the target pipeline. Specifically: If 4AC-2AB-2BC=0, then b=0, and h can be solved using the following formula: Wherein, a is the distance between the center points of adjacent detection coils; If 4AC-2AB-2BC≠0, then b and h are solved using the following formulas:

8. The deep-buried pipeline early warning detection method according to claim 7, characterized in that: The method of determining whether the detection coil group is close to the target pipeline is as follows: obtaining the induced electromotive force A, B, and C of the three detection coils from bottom to top, if the induced electromotive force of the detection coil group gradually increases and If the value is less than the set threshold, the drilling distance of each stage of the test hole is shortened and step S1 is repeated. If the value is greater than the set threshold, it is determined to be close to the target pipeline and the process goes to step S2.

9. The deep-buried pipeline early warning detection method according to claim 7, wherein in step S2, the position of the detection coil group is adjusted up and down to obtain multiple sets of data for verification.

10. The deep-buried pipeline early warning detection method according to claim 7, further comprising: Step S3: Based on the calculated vertical distance h between the detection coil group and the target pipeline, the test hole is further drilled, and b and h are re-obtained based on the induced electromotive force A, B, and C.

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