A trenchless geophysical exploration method for the location of reserved branch pipes in direct-buried heating pipelines

Abstract

This invention provides a trenchless geophysical exploration method for the location of reserved branch pipes in directly buried heating pipelines, comprising the following steps: Using a transient electromagnetic detector, the metal content in the near-surface soil is measured along both pipes of the heating pipeline, and potential value maps of the pipeline paths corresponding to the two pipes are plotted; if both potential value maps of the pipeline paths show convex curves at similar positions on the horizontal axis, and one is significantly wider than the other, it is preliminarily determined that a reserved branch pipe exists; The transient electromagnetic detector is then used to measure along both sides of the heating pipeline, and potential value maps of bypass paths are plotted; if the potential value map of the bypass path next to the wider convex curve shows a convex curve of the same width, and the potential value map of the bypass path next to the narrower convex curve does not show a convex curve, it is determined that a reserved branch pipe exists. This invention uses a transient electromagnetic method to detect the location of reserved branch pipes, achieving accurate positioning of reserved branch pipes without excavating the ground.

Description

Technical Field

[0001] This invention belongs to the field of trenchless geophysical exploration technology for direct-buried heating pipelines, and specifically relates to a trenchless geophysical exploration method for the location of reserved branch pipes in direct-buried heating pipelines. Background Technology

[0002] In northern my country, winter heating is provided by centralized heating systems, and direct-buried heating pipelines are a common method for laying pipelines in the primary network of urban heating systems. The primary heating network extends to the heat exchange stations in residential communities. According to urban planning, newly built residential complexes typically consist of multiple communities. Once a community is completed, the primary heating network needs to be laid to the corresponding community's heat exchange station, with branch pipes reserved for the communities yet to be completed, to connect with these heat exchange stations later. However, the construction period for residential complexes is long, the surrounding terrain changes significantly, and pipeline data is often incomplete or inaccurate, making it difficult to pinpoint the exact location of the reserved branch pipes, even if their approximate locations can be determined. While the route of direct-buried heating pipelines is generally determined using the pipe current method, this method cannot be used for reserved branch pipes as they lack grounding points. Excavation over large areas is prohibitively expensive. Therefore, finding the exact location of the reserved branch pipes remains a challenging problem. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a trenchless geophysical exploration method for the location of reserved branch pipes in direct-buried heating pipelines. The method uses transient electromagnetic methods to detect the location of reserved branch pipes, achieving accurate positioning of reserved branch pipes without excavating the ground.

[0004] The technical solution adopted in this invention is: a trenchless geophysical exploration method for the reserved branch pipe location of a direct-buried heating pipeline, comprising the following steps:

[0005] Step 1: On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground along the two pipes of the heating pipeline, and draw the pipeline path potential value diagram corresponding to the two pipes based on the potential value generated by the receiving coil caused by the returned secondary magnetic field.

[0006] Step 2: If there are convex curves at similar positions on the horizontal axis in the potential value diagrams of the two pipeline paths, let the two convex curves be convex curve A and convex curve B, and the width of convex curve A is significantly greater than the width of convex curve B, then it is preliminarily determined that there are reserved branch pipes at the positions corresponding to convex curve A and convex curve B.

[0007] Step 3: On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground along both sides of the heating pipe, and draw two bypass path potential value diagrams based on the potential value generated by the receiving coil by the returned secondary magnetic field.

[0008] Step 4: At the position corresponding to the horizontal coordinate of the convex curve A, if there is a convex curve C with a width similar to that of the convex curve A on the potential value diagram of the bypass path outside the pipe corresponding to the convex curve A, and there is no convex curve on the potential value diagram of the bypass path outside the pipe corresponding to the convex curve B, then it is determined that there is a reserved branch pipe at the position corresponding to the convex curve A and the direction of the reserved branch pipe is from the convex curve B towards the convex curve A.

[0009] Furthermore, in step 3, a transient electromagnetic detector is used to perform measurements at a distance of 2-5 meters along both sides of the heating pipeline.

[0010] Furthermore, the horizontal axis of the pipeline path potential value diagram and the bypass path potential value diagram represents the measurement distance, and the vertical axis represents the potential value.

[0011] Furthermore, the width of convex curve A is 2-4 times the width of convex curve B.

[0012] Working Principle: The main pipe and reserved branch pipes of the heating pipeline are installed perpendicularly. The metal content at the connection point is higher than at other locations on the main pipe. Based on this principle, transient electromagnetic methods are used to detect locations with significantly increased underground metal content along the main pipe of the heating pipeline. The heating pipeline consists of a supply pipe and a return pipe. At the connection point between the main pipe and the reserved branch pipe, one of the supply or return pipes will intersect with one of the reserved branch pipes, resulting in a larger area of ​​increased metal content. When measuring the metal content in near-surface soil using the transient electromagnetic method, the metal content affects the potential value generated by the receiving coil in the secondary magnetic field returned by the transient electromagnetic measurement. The potential value corresponding to the area with increased metal content will be higher than that of other areas. Therefore, the potential value map of the pipeline path corresponding to the supply and return pipes will show a convex curve at the corresponding location, and the width of one convex curve is more than twice that of the other.

[0013] To eliminate misjudgments caused by underground metal objects or pipe crossings, transient electromagnetic testing was performed again on both sides of the main heating pipe. The side closer to the narrower convex curve would not have a convex curve, while the side closer to the wider convex curve would show a convex curve of approximately the same width. This further improves the accuracy of determining the location of reserved branch pipes.

[0014] Compared with existing technologies, the advantages of this invention are as follows: This invention employs trenchless geophysical exploration to perform transient electromagnetic detection on the main heating pipeline and its sides buried underground, detecting the underground metal content and determining the location of reserved branch pipes based on the detection results. This invention only requires using a transient electromagnetic detector to detect four paths on the ground to determine the accurate location of the reserved branch pipes, eliminating the need for ground excavation, significantly reducing detection costs, and achieving an accuracy rate close to 100%. Attached Figure Description

[0015] Figure 1 This is a flowchart of an embodiment of the present invention;

[0016] Figure 2 A potential value diagram drawn for an embodiment of the present invention;

[0017] Figure 3 This is a pipeline routing diagram according to an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Embodiments of the present invention provide a trenchless geophysical exploration method for the location of reserved branch pipes in directly buried heating pipelines, such as... Figure 1 As shown, it includes the following steps:

[0020] Step 1: Determine the approximate location of the reserved branch pipes based on the pipeline data. On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground along the two main heating pipes, and draw a pipeline path potential value diagram corresponding to the two pipes based on the potential value generated by the receiving coil caused by the returned secondary magnetic field.

[0021] Step 2: As Figure 2 As shown, in the potential value diagrams of the two pipeline paths, there are convex curves at positions with similar horizontal coordinates. Let the convex curve corresponding to the return water pipe be convex curve A, and the convex curve corresponding to the supply water pipe be convex curve B. The width of convex curve A is approximately 2.5 times the width of convex curve B, and the width of convex curve A is significantly greater than the width of convex curve B. It is preliminarily determined that there may be reserved branch pipes at the positions corresponding to convex curve A and convex curve B.

[0022] If the above-mentioned protruding curve does not appear on the pipeline path potential value diagram, then repeat step 1, change the location, and re-perform transient electromagnetic detection.

[0023] Step 3: On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground at a distance of 3 meters on each side of the heating pipe. Locate bypass A 3 meters outside the heating pipe and bypass B 3 meters outside the return pipe. Draw bypass path potential diagrams for bypass A and bypass B based on the measurement results.

[0024] Step 4: At the position corresponding to the horizontal axis of convex curve A, there exists a convex curve C on the bypass path potential value diagram of bypass B with a width similar to that of convex curve A, and there is no convex curve on the bypass path potential value diagram of bypass A. This indicates that there is a reserved branch pipe at the positions corresponding to convex curves A and B, and the direction of the reserved branch pipe is from convex curve B towards convex curve A. If the bypass path potential value diagrams of bypass A and bypass B do not meet the above judgment criteria, it may be due to the presence of underground metal objects or cross-pipes.

[0025] The horizontal axis of both the pipeline path potential diagram and the bypass path potential diagram represents the measurement distance, and the vertical axis represents the potential value. To better compare the four potential diagrams, Figure 2 The four potential value diagrams were arranged according to the actual measurement locations. Figure 3 The dashed lines in the diagram represent the measurement paths for bypass A and bypass B. This embodiment measured the location of the reserved branch pipe, and excavation verification confirmed the accuracy of the reserved branch pipe's location.

[0026] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of the present invention. The scope of protection of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and protection scope of the present invention, to achieve the above-mentioned technical effects, or any equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention.

Claims

1. A trenchless geophysical exploration method for the location of reserved branch pipes in a direct-buried heating pipeline, characterized in that: Includes the following steps: Step 1: On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground along the two pipes of the heating pipeline, and draw the pipeline path potential value diagram corresponding to the two pipes based on the potential value generated by the receiving coil caused by the returned secondary magnetic field. Step 2: If there are convex curves at similar positions on the horizontal axis in the potential value diagrams of the two pipeline paths, let the two convex curves be convex curve A and convex curve B, and the width of convex curve A is significantly greater than the width of convex curve B, then it is preliminarily determined that there are reserved branch pipes at the positions corresponding to convex curve A and convex curve B. Step 3: On the ground, use a transient electromagnetic detector to measure the metal content in the soil near the ground along both sides of the heating pipe, and draw two bypass path potential value diagrams based on the potential value generated by the receiving coil by the returned secondary magnetic field. Step 4: At the position corresponding to the horizontal coordinate of the convex curve A, if there is a convex curve C with a width similar to that of the convex curve A on the potential value diagram of the bypass path outside the pipe corresponding to the convex curve A, and there is no convex curve on the potential value diagram of the bypass path outside the pipe corresponding to the convex curve B, then it is determined that there is a reserved branch pipe at the position corresponding to the convex curve A and the direction of the reserved branch pipe is from the convex curve B towards the convex curve A. The horizontal axis of the pipeline path potential value diagram and the bypass path potential value diagram represents the measurement distance, and the vertical axis represents the potential value.

2. The trenchless geophysical exploration method for the reserved branch pipe location of the direct-buried heating pipeline as described in claim 1, characterized in that: In step 3, a transient electromagnetic detector is used to measure at a distance of 2-5 meters on both sides of the heating pipeline.

3. The trenchless geophysical exploration method for the reserved branch pipe location of the direct-buried heating pipeline as described in claim 1, characterized in that: The width of convex curve A is 2-4 times the width of convex curve B.

Images