A landfill leakage detection system based on transient electromagnetic method

Abstract

A landfill leakage detection system based on transient electromagnetic method, comprising an overlapping loop module, a transmitting transmission line, a receiving transmission line, a transmitter and a receiver; the overlapping loop module comprises a transmitting coil, a receiving coil and a corrosion-proof buckle; the transmitting coil and the receiving coil are concentrically arranged in the same plane; a plurality of corrosion-proof buckles are arranged between the transmitting coil and the receiving coil in the peripheral direction, the corrosion-proof buckle comprises a lower supporting piece and an upper pressing piece, the lower supporting piece is provided with a lower supporting groove, the upper pressing piece is provided with an upper pressing groove, and the lower supporting piece and the upper pressing piece are fixedly connected through bolts; one end of the transmitting transmission line is connected with the transmitting coil, and the other end is used for connecting the transmitting terminal of the transmitter; one end of the receiving transmission line is connected with the receiving coil, and the other end is used for connecting the receiving terminal of the receiver; a plurality of overlapping loop modules are laid between the HDPE film and the GCL layer of the landfill. The embodiment has the advantages of simple structure, convenient detection and large-area rapid detection of the specific position of leakage.

Description

Technical Field

[0001] This application relates to the field of environmental monitoring technology, and in particular to a landfill leakage detection system based on transient electromagnetic method. Background Technology

[0002] With the continuous improvement of residents' living standards, the amount of solid waste is also increasing daily. Currently, landfill is one of the main methods of solid waste disposal. Landfill seepage prevention systems mainly use HDPE membranes (High Density Polyethylene), which have characteristics such as low permeability and corrosion resistance. HDPE membranes may be damaged due to construction work, aging, etc., leading to leachate leakage. Therefore, quickly locating the leakage point is crucial for landfill environmental management.

[0003] Existing landfill detection systems using geosynthetic clay liner (GCL) as the underlying medium include transmission line method, fiber optic method, and eddy current positioning method. The conductive fibers used in the transmission line method and the optical fibers used in the fiber optic method both require a high-quality foundation layer, necessitating compaction and leveling of the underlying soil layer during installation. However, as landfilling continues, the soil layer under the HDPE membrane collapses, causing data loss due to sensor misalignment, leading to false positives and false negatives. The eddy current positioning method requires densely laying out detection units over a large area of ​​the detection layer, resulting in complex deployment and low detection efficiency.

[0004] Based on the problems in existing technologies, there is an urgent need for a landfill leakage location detection system that is simple in structure, convenient to detect, and capable of rapidly detecting leakage over a large area and identifying the specific location of the leakage. Summary of the Invention

[0005] To address at least one of the problems mentioned in the background art, embodiments of this application provide a landfill leakage detection system based on transient electromagnetic method. This system has the advantages of simple structure, convenient detection, and the ability to quickly detect leakage over a large area and pinpoint its location, providing a new approach for locating landfill leakage.

[0006] To achieve the above objectives, this application provides a landfill leakage detection system based on transient electromagnetic method, including an overlapping loop module, a transmitting transmission line, a receiving transmission line, a transmitter, and a receiver; The overlapping loop module includes a transmitting coil, a receiving coil, and anti-corrosion clips; the transmitting coil and the receiving coil are concentrically arranged in the same plane, and the transmitting coil is located on the periphery of the receiving coil; along the outer circumferential direction, multiple anti-corrosion clips are spaced apart between the transmitting coil and the receiving coil, and the anti-corrosion clips include a lower support and an upper pressing member arranged opposite to each other. The lower support is provided with a lower support groove for respectively clamping the transmitting coil and the receiving coil, and the upper pressing member is provided with an upper pressing groove for respectively pressing the transmitting coil and the receiving coil. The lower support and the upper pressing member are fixedly connected by bolts. One end of the transmitting transmission line is connected to the transmitting coil, and the other end is used to connect to the transmitting terminal of the transmitter; one end of the receiving transmission line is connected to the receiving coil, and the other end is used to connect to the receiving terminal of the receiver. Multiple overlapping loop modules are laid between the HDPE membrane and GCL layer in the landfill. Each overlapping loop module is connected to its corresponding transmit and receive transmission lines. The transmitter transmits a signal to the transmit coil of the corresponding overlapping loop module via the transmit transmission line, and the receive coil of the corresponding overlapping loop module transmits a signal back to the receiver via the receive transmission line, thereby detecting leakage in the corresponding area of ​​the overlapping loop module.

[0007] In one feasible implementation, the lower support groove and the upper pressure groove are interlocked to form a circular hole structure, the inner surfaces of the lower support groove and the upper pressure groove are provided with anti-slip textures, and both sides of the lower support and the upper pressure member are provided with detachable fastening bolts.

[0008] In one feasible implementation, the spacing between the transmitting coil and the receiving coil in the same overlapping loop module ranges from 1 to 10 cm. The spacing between adjacent overlapping loop modules ranges from 4.5 to 5.5 meters.

[0009] In one feasible implementation, the overlapping loop module is a rectangular loop module, and both the transmitting coil and the receiving coil are rectangular coils, with the side length of the rectangular coil of the transmitting coil being 50-100cm.

[0010] In one feasible implementation, the overlapping loop module is a circular loop module, and both the transmitting coil and the receiving coil are circular coils, with the diameter of the transmitting coil being 50-100cm.

[0011] In one feasible implementation, a plurality of the overlapping loop modules are distributed in a matrix or circumferential manner between the HDPE membrane and the GCL layer in the landfill.

[0012] In one feasible implementation, both the transmitting coil and the receiving coil include a coil layer made of copper foil or copper wire, and the coil layer of the receiving coil has a built-in iron-nickel-based amorphous alloy magnetic core.

[0013] In one feasible implementation, the outer periphery of the coil layers of both the transmitting coil and the receiving coil is covered with a resin skeleton, and the outer periphery of the skeleton is covered with a sealing layer.

[0014] In one feasible implementation, the outer layer of the sealing layer of the transmitting coil and the receiving coil, as well as the outer layer of the anti-corrosion buckle, are all coated with an anti-corrosion layer.

[0015] In one feasible implementation, the transmission line is a coaxial cable, with the inner core at one end of the coaxial cable connected to one terminal of the transmitting coil, the shielding layer at the same end connected to the other terminal of the transmitting coil, and the other end of the coaxial cable connected to the transmitting terminal of the transmitter via an aviation plug. The receiving transmission line is a coaxial cable. The inner core of one end of the coaxial cable is connected to one terminal of the receiving coil, and the shielding layer at the same end is connected to the other terminal of the receiving coil. The other end of the coaxial cable is connected to the receiving terminal of the receiver via an aviation plug.

[0016] This application provides a landfill leakage detection system based on transient electromagnetic method, including an overlapping loop module, a transmitting transmission line, a receiving transmission line, a transmitter, and a receiver. Multiple overlapping loop modules are laid between the HDPE membrane and GCL layer in the landfill. Each overlapping loop module is connected to its corresponding transmitting and receiving transmission lines. The transmitter transmits a signal to the transmitting coil of the corresponding overlapping loop module via the transmitting transmission line, and the receiving coil of the corresponding overlapping loop module transmits a signal back to the receiver via the receiving transmission line.

[0017] During operation, the transmitter and receiver are sequentially connected to the corresponding transmit and receive transmission lines of each overlapping loop module. After startup, the transmitter outputs a pulsed current to the transmit coil via the transmit transmission line according to preset parameters. The transmit coil receives this pulsed current, forming a primary pulsed electromagnetic field. The pulsed current can be a bipolar step waveform. At the instant the primary pulsed electromagnetic field is turned off, eddy currents are generated in the detected area around the transmit coil due to electromagnetic induction, forming a secondary electromagnetic field. The receive coil is concentrically aligned with the transmit coil, generating electromagnetic coupling and synchronously capturing this secondary electromagnetic field. The acquired signal is then transmitted to the receiver via the receive transmission line. The receiver conditions, amplifies, filters, and reduces noise in the received signal, outputting a secondary field time-domain signal, which is displayed as a secondary field attenuation curve. Each overlapping loop module is excited separately to obtain its secondary field attenuation curve. Because the overlapping loop modules near the leak point exhibit a stronger eddy current effect due to the high conductivity of the leachate, resulting in higher signal strength, when the attenuation rate of the secondary field attenuation curve of a certain overlapping loop module is greater than the normal interlayer attenuation rate, that overlapping loop module is determined to be a leak-related overlapping loop module surrounding the leak point. The receiver calculates the planar position of the leak point using the coordinates of the leak-related overlapping loop modules combined with a preset weighted average algorithm.

[0018] This application embodiment constructs a landfill leakage detection system by arranging multiple overlapping loop modules between the HDPE membrane and GCL layer in the landfill and connecting them to a transmitter and receiver. This system features a simple structure and convenient setup. Corrosion-resistant clips ensure concentric alignment of the transmitting and receiving coils, improving adhesion to interlayer deformation and enhancing the accuracy of detection results. Utilizing the electromagnetic induction effect of pulse signals between the transmitting and receiving coils, a certain area around each overlapping loop module is used as the detection zone. Taking advantage of the stronger eddy current effect of the leachate, overlapping loop modules associated with leakage are selected. The specific location of the leakage point is then calculated. This method eliminates the need for dense deployment and offers advantages such as convenient detection and rapid detection of large-area leaks, providing a new approach for locating landfill leaks. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a landfill structure provided in an embodiment of this application; Figure 2 A schematic diagram of a landfill leakage detection system based on transient electromagnetic method provided in an embodiment of this application; Figure 3 This is a schematic diagram of the anti-corrosion buckle structure provided in the embodiments of this application; Figure 4 A schematic diagram illustrating the application status of a landfill leakage detection system based on transient electromagnetic method under leakage conditions, provided for an embodiment of this application. Figure 5 A schematic diagram illustrating the application status of a landfill leakage detection system based on transient electromagnetic method under no-leakage conditions, as provided in an embodiment of this application. Figure 6 The secondary field attenuation curve of a landfill leakage detection system based on transient electromagnetic method provided in this application embodiment under leakage conditions; Figure 7 The secondary field attenuation curve of a landfill leakage detection system based on transient electromagnetic method provided in this application embodiment is shown in the case of no leakage.

[0021] Explanation of reference numerals in the attached figures: 10 - Landfill layer; 20 - Conduit layer; 30 - HDPE membrane; 40 - GCL layer; 100 - Landfill Leakage Detection System; 110 - Overlapping loop module; 111 - Transmitting coil; 112 - Receiving coil; 113 - Coil layer; 114 - Iron-nickel based amorphous alloy magnetic core; 115 - Frame; 116 - Corrosion-resistant buckle; 117 - Lower support; 118 - Upper pressure component; 119 - Bolt; 120 - Transmission line; 130 - Receive transmission line; 140 - Transmitter; 150 - Receiver. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. It is worth noting that the embodiments described in the accompanying drawings are only some embodiments of this application, and not all embodiments. That is, the embodiments described with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0023] The following will combine Figures 1-7 This application describes a landfill leakage detection system 100 based on transient electromagnetic method provided in an embodiment.

[0024] This application provides a landfill leakage detection system 100 based on transient electromagnetic method, such as... Figure 2 and Figure 3As shown, it includes an overlapped loop module 110, a transmit transmission line 120, a receive transmission line 130, a transmitter 140, and a receiver 150.

[0025] The overlapping loop module 110 includes a transmitting coil 111, a receiving coil 112, and corrosion-resistant clips 116. The transmitting coil 111 and the receiving coil 112 are concentrically arranged in the same plane, with the transmitting coil 111 located around the receiving coil 112. Along the outer periphery, multiple corrosion-resistant clips 116 are spaced apart between the transmitting coil 111 and the receiving coil 112. Each corrosion-resistant clip 116 includes a lower support 117 and an upper pressure member 118 arranged opposite to each other. The lower support 117 has a lower support groove for respectively clamping the transmitting coil 111 and the receiving coil 112, and the upper pressure member 118 has an upper pressure groove for respectively pressing the transmitting coil 111 and the receiving coil 112. The lower support 117 and the upper pressure member 118 are fixedly connected by bolts 119.

[0026] One end of the transmitting line 120 is electrically connected to the transmitting coil 111, and the other end is used to electrically connect to the transmitting terminal of the transmitter 140. One end of the receiving line 130 is electrically connected to the receiving coil 112, and the other end is used to electrically connect to the receiving terminal of the receiver 150.

[0027] Multiple overlapping loop modules 110 are laid between the HDPE membrane 30 and the GCL layer 40 in the landfill. Each overlapping loop module 110 is connected to its corresponding transmission line 120 and receiving line 130. The transmitter 140 transmits a signal to the transmission coil 111 of the corresponding overlapping loop module 110 via the transmission line 120, and the receiving coil 112 of the corresponding overlapping loop module 110 transmits a signal back to the receiver 150 via the receiving line 130, thereby detecting leakage in the corresponding area of ​​the overlapping loop module 110.

[0028] like Figure 1 As shown, the landfill consists of a landfill layer 10, a drainage layer 20, an HDPE membrane 30, and a GCL layer 40 from top to bottom. During the construction phase of the landfill impermeable layer, before the HDPE membrane 30 is laid and after the GCL layer 40 is covered, a landfill leakage detection system 100 based on transient electromagnetic method provided in this application embodiment is laid. Multiple overlapping loop modules 110 are embedded in the planar area between the two layers. One end of the transmitting transmission line 120 is electrically connected to the terminal of the transmitting coil 111, and the other end extends along the slope to the off-site transmitter 140. One end of the receiving transmission line 130 is electrically connected to the terminal of the receiving coil 112, and the other end extends along the slope to the off-site receiver 150.

[0029] The transient electromagnetic transmitter can be a YCS400A model, with a turn-off time of 0.1-10μs, capable of emitting bipolar square waves to rapidly generate a single-pulse electromagnetic field. The receiver can also be a YCS400A model. The transmitter 140 is equipped with a display module with display function, and the receiver 150 is equipped with a positioning display module with integrated calculation and control functions.

[0030] During operation, transmitter 140 and receiver 150 are sequentially connected to the corresponding transmit transmission line 120 and receive transmission line 130 of each overlapping loop module 110. After transmitter 140 starts, it outputs a pulse current to transmit coil 111 via transmit transmission line 120 according to preset parameters. Transmit coil 111 receives the pulse current to form a primary pulse electromagnetic field. The pulse current can be a bipolar step waveform. At the instant the primary pulse electromagnetic field is turned off, eddy currents are generated in the detected area around the transmit coil due to electromagnetic induction, forming a secondary electromagnetic field. Receiver coil 112 is concentrically aligned with transmit coil 111, generating electromagnetic coupling, synchronously capturing the secondary electromagnetic field, and transmitting the acquired signal to receiver 150 via receive transmission line 130. Receiver 150 conditions, amplifies, filters, and reduces noise in the received signal, outputting a secondary field time-domain signal, which is displayed as a secondary field attenuation curve. Each overlapping loop module 110 is excited to obtain the secondary field attenuation curve of each overlapping loop module 110. Because the overlapping loop modules 110 near the leak point have a stronger eddy current effect due to the high conductivity of the leachate, resulting in higher signal strength, when the attenuation rate of the secondary field attenuation curve of a certain overlapping loop module 110 is greater than the normal interlayer attenuation rate, that overlapping loop module 110 is determined to be a leak-related overlapping loop module surrounding the leak point. The receiver 150 calculates the planar position of the leak point by combining the coordinates of the leak-related overlapping loop modules with a preset weighted average algorithm.

[0031] Specifically, the receiver 150 includes a signal conditioning unit (containing amplification and filtering circuits), a data processing unit, and a positioning display module. The signal conditioning unit amplifies the received weak signal and filters out power frequency interference. The signal is converted into a digital signal using a 16-bit ADC analog-to-digital converter. The data processing unit identifies leakage anomalies by plotting a secondary field attenuation curve. For example, refer to... Figure 4 and Figure 5 A state diagram, in comparison Figure 6 and Figure 7 The secondary field attenuation curve, where the vertical axis represents the signal strength. I The horizontal axis represents time. t It can be known that Figure 6 The leakage secondary field attenuation rate is shown to be significantly greater than that of the previous one. Figure 7 When there is no leakage and the interlayer medium decay rate is normal, it is determined that... Figure 6 The image shows the leakage-related overlapping loop module.

[0032] The positioning display module, combined with the coordinates of the leakage correlation overlapping loop module, calculates the planar location of the leakage point using a weighted average algorithm, as shown in the following formula: (1) (2) in, A Let x be the x-coordinate of the leakage point. B Let be the ordinate of the leakage point, ( a i , b i () represents the coordinates of the leakage-related overlapping loop module. I i For the first i The signal strength was collected by the leakage correlation overlapping loop module. The sampling time point was 0.3s after the first pulse electromagnetic field was turned off. n This represents the number of leakage-related overlapping loop modules involved in the calculation.

[0033] The location of the leak can be calculated by selecting at least three overlapping loop modules associated with leakage, extracting the corresponding signal strengths, and performing a weighted average. For example, the overlapping loop modules associated with leakage are: coil I (coordinates: (10, 15), signal strength: 80mV); coil II (coordinates: (15, 15), signal strength: 60mV); and coil III (coordinates: (10, 20), signal strength: 40mV). The weight of coil I is 80 / (80+60+40) = 0.44, and its weighted coordinates are (10×0.44=4.4, 15×0.44=6.6). The weighted coordinates of coils II and III are (5, 5) and (2.2, 4.4), respectively. Therefore, the leak point coordinates are (4.4+5+2.2=11.6, 6.6+5+4.4=16).

[0034] Understandably, the transmitting coil 111 and receiving coil 112 are initially designed to be concentrically arranged with a fixed spacing. Ideally, they are parallel to the HDPE film 30 to ensure electromagnetic coupling efficiency. Anti-corrosion clips 116 are arranged circumferentially along the transmitting coil 111 and receiving coil 112. These clips secure the relative positions of the transmitting coil 111 and receiving coil 112. Bolts 119 tighten the transmitting coil 111 and receiving coil 112, preventing excessive looseness leading to displacement or excessive tightness causing coil damage. This ensures the transmitting coil 111 and receiving coil 112 are concentrically aligned, allowing the overlapping loop module 110 to fit seamlessly with interlayer deformation. Therefore, even if the overall plane is deformed due to the external force of the base layer, as long as the concentric relationship between the transmitting coil 111 and the receiving coil 112 is not disrupted, the electromagnetic coupling failure caused by the interlayer displacement of the landfill can still be avoided, and the signal with a secondary field attenuation rate faster than that of the normal medium in the leachate area can be normally collected, thereby improving the accuracy of the detection results and overcoming the false detection problem caused by device offset in the transmission line method and the fiber optic method.

[0035] This embodiment of the application constructs a landfill leakage detection system by arranging multiple overlapping loop modules 110 between the HDPE membrane 30 and the GCL layer 40 in the landfill and connecting them to a transmitter 140 and a receiver 150. This system features a simple structure and convenient setup. Anti-corrosion clips 116 ensure concentric alignment of the transmitting coil 111 and the receiving coil 112, improving the fit to interlayer deformation and enhancing the accuracy of the detection results. Utilizing the electromagnetic induction effect of pulse signals between the transmitting coil 111 and the receiving coil 112, a certain area around each overlapping loop module 110 is used as the detection area. Combined with the stronger eddy current effect of the leachate, overlapping loop modules associated with leakage are selected, and the specific location of the leakage point is calculated. This method eliminates the need for dense deployment and offers advantages such as convenient detection and rapid detection of large-area leaks, providing a new approach for locating landfill leaks.

[0036] In one feasible implementation, the lower support groove and the upper pressure groove are interlocked as a circular hole structure, and the inner surfaces of the lower support groove and the upper pressure groove are provided with anti-slip textures. Both sides of the lower support 117 and the upper pressure member 118 are provided with detachable fastening bolts 119.

[0037] The lower support 117, upper pressure member 118, and detachable fastening bolt 119 can all be made of polypropylene plastic. The size of the circular hole formed by the lower support groove and upper pressure groove matches the total thickness of the transmitting coil 111 and the receiving coil 112. The anti-slip texture design increases the friction between the corrosion-resistant clip 116 and the coil. During installation, the tightness of the circular hole is adjusted by the cooperation of the detachable fastening bolt 119 and the nut to avoid displacement due to excessive looseness or cracking of the coil due to excessive tightness.

[0038] In one feasible implementation, the spacing between the transmitting coil 111 and the receiving coil 112 in the same overlapping loop module 110 ranges from 1 to 10 cm, preferably 3 to 5 cm.

[0039] The spacing between adjacent overlapping loop modules 110 ranges from 4.5 to 5.5 meters.

[0040] The transmitting coil 111 generates a primary pulsed electromagnetic field through pulsed current excitation. The receiving coil 112 is an induction coil of the same specification, arranged concentrically with the transmitting coil 111 to form an overlapping structure, used to collect the secondary electromagnetic field signal induced by the highly conductive leachate, thereby improving electromagnetic coupling efficiency. Increasing the distance between the transmitting coil 111 and the receiving coil 112 to 10 cm can also prevent signal saturation.

[0041] By considering the size design of the overlapping loop module 110 and the range of the secondary electromagnetic field signal generated by electromagnetic induction in the area to be detected, the spacing range between adjacent overlapping loop modules 110 can be set. This avoids the spacing range being too large, which would not cover the entire area to be detected and affect the accuracy of the detection results, and also avoids the detection range being too small, which would cause too much overlap in the detected area, resulting in increased detection time and wasted resources. Furthermore, with this setting, the overlapping loop modules 110 are laid out at grid intervals, eliminating the need for dense deployment and enabling large-area synchronous monitoring.

[0042] In one feasible implementation, the overlapping loop module 110 is a rectangular loop module, and both the transmitting coil 111 and the receiving coil 112 are rectangular coils, with the side length of the rectangular coil of the transmitting coil 111 being 50-100cm.

[0043] Alternatively, the overlapping loop module 110 is a circular loop module, with both the transmitting coil 111 and the receiving coil 112 being circular coils, and the diameter of the circular coil of the transmitting coil 111 being 50-100cm.

[0044] The size of the coil directly affects the detection depth; smaller coils can be used for shallow detection, while larger coils can be used for deep detection. The coil size range in this embodiment can meet the detection requirements of most landfills. Furthermore, setting the transmitting coil 111 and receiving coil 112 as rectangular or circular coils facilitates grid-like arrangement.

[0045] For a rectangular loop module, it can form four square coils with equal sides, or it can be a rectangular coil with each side having a length in the range of 50-100cm, for example, a short side of 50cm and a long side of 60cm. Each side of the rectangular coil can be equipped with two anti-corrosion clips 116, with a spacing of 20-30cm between the two clips. This ensures good concentric alignment between the transmitting coil 111 and the receiving coil 112. Even under interlayer displacement, the anti-corrosion clips 116 ensure that the transmitting coil 111 and the receiving coil 112 move in close coordination, avoiding coupling failure caused by interlayer displacement.

[0046] In one feasible implementation, multiple overlapping loop modules 110 are distributed in a matrix or circumferential manner between the HDPE membrane 30 and the GCL layer 40 in the landfill.

[0047] This allows for uniform division of the layers, facilitating positioning and subsequent calculations.

[0048] In one feasible implementation, such as Figure 3 As shown, both the transmitting coil 111 and the receiving coil 112 include a coil layer 113 made of copper foil or copper wire, and the coil layer 113 of the receiving coil 112 has a built-in iron-nickel-based amorphous alloy magnetic core 114.

[0049] Copper foil or copper wire materials have good electromagnetic coupling effects. Each side of the receiving coil 112 can be equipped with a certain length of iron-nickel-based amorphous alloy magnetic core 114, which helps to improve the magnetic field induction sensitivity. For example, in a square receiving coil 112 with a side length of 50cm, each side of the coil can be equipped with an iron-nickel-based amorphous alloy magnetic core 114 with a diameter of 5mm and a length of 40cm.

[0050] In one feasible implementation, such as Figure 3 As shown, the outer periphery of the coil layer 113 of both the transmitting coil 111 and the receiving coil 112 is covered with a resin skeleton 115, and the outer periphery of the skeleton 115 is covered with a sealing layer (not shown).

[0051] The transmitting coil 111 and receiving coil 112 form a composite protective structure using a phenolic resin skeleton 115 and a silicone sealing layer. Specifically, the outer layer of the coil layer 113 of both the transmitting coil 111 and the receiving coil 112 is covered with a 5mm phenolic resin skeleton 115. The phenolic resin skeleton 115 provides structural support, increases coil strength, reduces deformation, enhances structural stability, and prevents the coil layer 113 from breaking due to the weight of the landfill. A 2-3mm silicone sealing layer is applied to the skeleton 115. This silicone sealing layer is resistant to leachate corrosion, heat-resistant, and possesses a certain degree of elasticity, reducing the coefficient of friction between the coil and the HDPE film 30 and GCL layer 40. When relative movement occurs between layers due to landfill pressure (such as soil collapse or local subsidence), the low coefficient of friction can reduce the overall sliding displacement of the overlapping loop module 110 between layers. The coil can undergo adaptive elastic deformation with the interlayer deformation of HDPE film 30 and GCL layer 40, always maintaining contact with the two media, further assisting the anti-corrosion buckle 116 in maintaining the relative position stability of transmitting coil 111 and receiving coil 112.

[0052] In one feasible implementation, the outer layer of the sealing layer of the transmitting coil 111 and the receiving coil 112, as well as the outer layer of the anti-corrosion buckle 116, are coated with an anti-corrosion layer (not shown).

[0053] During preparation, the skeleton 115 of the transmitting coil 111 and the receiving coil 112 and the sealing layer are prepared first, then the anti-corrosion buckle 116 is installed, and finally the anti-corrosion layer is applied.

[0054] In one feasible implementation, the transmission line 120 is a coaxial cable. The inner core of one end of the coaxial cable of the transmission line 120 is electrically connected to one terminal of the transmission coil 111, and the shielding layer at the same end is electrically connected to the other terminal of the transmission coil 111. The other end of the coaxial cable of the transmission line 120 is electrically connected to the transmission terminal of the transmitter 140 via an aviation plug.

[0055] The receiving transmission line 130 is a coaxial cable. The inner core of one end of the coaxial cable of the receiving transmission line 130 is electrically connected to one terminal of the receiving coil 112, and the shielding layer at the same end is electrically connected to the other terminal of the receiving coil 112. The other end of the coaxial cable of the receiving transmission line 130 is electrically connected to the receiving terminal of the receiver 150 via an aviation plug.

[0056] The coaxial cable is covered with a corrosion-resistant polyethylene sheath for low-loss transmission of electromagnetic signals, making it suitable for slope soil and leachate corrosive environments. The connection between the coaxial cable and the coil can be treated with a skeleton 115, a silicone sealing layer, and an anti-corrosion coating. Furthermore, the terminal connection between the coaxial cable and the coil can be filled with silicone rubber to prevent moisture intrusion.

[0057] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" in the description of this application should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] The terms “upper,” “lower,” “front,” “back,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0059] The term "multiple" means two or more, unless otherwise specified precisely.

[0060] The terms “first,” “second,” “third,” “fourth,” etc., (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can include implementations in sequences other than those illustrated or described herein.

[0061] The terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A landfill leakage detection system based on transient electromagnetic method, characterized in that, Includes an overlapped loop module, a transmit transmission line, a receive transmission line, a transmitter, and a receiver; The overlapping loop module includes a transmitting coil, a receiving coil, and a corrosion-resistant clip; the transmitting coil and the receiving coil are arranged concentrically in the same plane, and the transmitting coil is located outside the receiving coil; Along the outer periphery, a plurality of anti-corrosion clips are provided at intervals between the transmitting coil and the receiving coil. The anti-corrosion clips include a lower support and an upper pressing member arranged opposite to each other. The lower support is provided with a lower support groove for respectively clamping the transmitting coil and the receiving coil. The upper pressing member is provided with an upper pressing groove for respectively pressing the transmitting coil and the receiving coil. The lower support and the upper pressing member are fixedly connected by bolts. One end of the transmitting transmission line is connected to the transmitting coil, and the other end is used to connect to the transmitting terminal of the transmitter; one end of the receiving transmission line is connected to the receiving coil, and the other end is used to connect to the receiving terminal of the receiver. Multiple overlapping loop modules are laid between the HDPE membrane and GCL layer in the landfill. Each overlapping loop module is connected to its corresponding transmit and receive transmission lines. The transmitter transmits a signal to the transmit coil of the corresponding overlapping loop module via the transmit transmission line, and the receive coil of the corresponding overlapping loop module transmits a signal back to the receiver via the receive transmission line, thereby detecting leakage in the corresponding area of ​​the overlapping loop module.

2. The landfill leakage detection system based on transient electromagnetic method according to claim 1, characterized in that, The lower support groove and the upper pressure groove are interlocked to form a circular hole structure. The inner surfaces of the lower support groove and the upper pressure groove are provided with anti-slip textures. Both sides of the lower support and the upper pressure are provided with detachable fastening bolts.

3. The landfill leakage detection system based on transient electromagnetic method according to claim 1, characterized in that, In the same overlapping loop module, the spacing between the transmitting coil and the receiving coil ranges from 1 to 10 cm; The spacing between adjacent overlapping loop modules ranges from 4.5 to 5.5 meters.

4. The landfill leakage detection system based on transient electromagnetic method according to claim 3, characterized in that, The overlapping loop module is a rectangular loop module, and both the transmitting coil and the receiving coil are rectangular coils, with the side length of the rectangular coil of the transmitting coil being 50-100cm.

5. A landfill leakage detection system based on transient electromagnetic method according to claim 3, characterized in that, The overlapping loop module is a circular loop module, and both the transmitting coil and the receiving coil are circular coils, with the diameter of the transmitting coil being 50-100cm.

6. A landfill leakage detection system based on transient electromagnetic method according to any one of claims 1-5, characterized in that, Multiple overlapping loop modules are distributed in a matrix or circular pattern between the HDPE membrane and GCL layer in the landfill.

7. A landfill leakage detection system based on transient electromagnetic method according to any one of claims 1-5, characterized in that, Both the transmitting coil and the receiving coil include a coil layer made of copper foil or copper wire, and the coil layer of the receiving coil has a built-in iron-nickel-based amorphous alloy magnetic core.

8. A landfill leakage detection system based on transient electromagnetic method according to claim 7, characterized in that, The outer periphery of the coil layers of both the transmitting coil and the receiving coil is covered with a resin skeleton, and the outer periphery of the skeleton is covered with a sealing layer.

9. A landfill leakage detection system based on transient electromagnetic method according to claim 8, characterized in that, The outer layer of the sealing layer of the transmitting coil and the receiving coil, as well as the outer layer of the anti-corrosion buckle, are all coated with an anti-corrosion layer.

10. A landfill leakage detection system based on transient electromagnetic method according to any one of claims 1-5, characterized in that, The transmission line is a coaxial cable. The inner core of one end of the coaxial cable is connected to one terminal of the transmitting coil, and the shielding layer at the same end is connected to the other terminal of the transmitting coil. The other end of the coaxial cable is connected to the transmitting terminal of the transmitter via an aviation plug. The receiving transmission line is a coaxial cable. The inner core of one end of the coaxial cable is connected to one terminal of the receiving coil, and the shielding layer at the same end is connected to the other terminal of the receiving coil. The other end of the coaxial cable is connected to the receiving terminal of the receiver via an aviation plug.

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