Plastic water supply pipeline leakage monitoring and early warning method and equipment based on resistance and capacitance

Abstract

The invention relates to a plastic water supply pipeline leakage monitoring and early warning method and equipment based on resistors and capacitors, and belongs to the technical field of water supply pipeline leakage monitoring. Two parallel conductive plastic fusion bodies extending along the length of the pipeline are formed on the surface of the plastic pipeline body through a forming process; resistance and capacitance detection terminals are arranged on the pipeline at intervals, three electrodes are arranged to be electrically connected with the two independent conductive plastic fusion bodies at the position respectively, and a grounding electrode is connected with the ground. The device is used for detecting the change conditions of capacitance and resistance between two conductive plastic fusion bodies and between each conductive plastic fusion body and the ground in real time, setting a capacitance early warning threshold value and a resistance early warning threshold value, judging pipeline leakage when one capacitance increment exceeds the early warning threshold value and one resistance decrement exceeds the early warning threshold value, and judging pipeline leakage when the other capacitance increment exceeds the early warning threshold value and the other resistance decrement exceeds the early warning threshold value. And triggering alarm. The problems of high omission ratio, high cost, poor stability and the like in the prior art are solved, and an efficient solution is provided for water supply network leakage treatment.

Description

Technical Field

[0001] This invention relates to a method and device for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance, belonging to the field of water supply pipe leakage monitoring technology. Background Technology

[0002] According to data from the "Urban and Rural Construction Statistical Yearbook (2021)" released by the Ministry of Housing and Urban-Rural Development in October 2022, the total public water supply in cities and counties nationwide in 2021 was 74.216 billion cubic meters, with a leakage of 9.408 billion cubic meters, resulting in a comprehensive leakage rate of 12.68%. Statistics from the 2017 (Second) Water Supply Summit Forum show that the average leakage rate of pipe networks in 654 cities nationwide exceeded 15%, with the situation being even more severe in rural areas. Overall, there is still a significant gap compared to the current national basic leakage assessment target of 12% and the average level of 6-8% in developed countries.

[0003] my country's per capita water resources are only 35% of the world average. In water-scarce cities in the north, water supply relies heavily on inter-regional water transfers or groundwater. Pipeline leaks not only waste a lot of water resources but also cause significant economic losses to enterprises, making efficient management urgently needed.

[0004] To prevent freezing and damage, main water supply pipes are buried 0.7-2 meters underground, making leaks difficult to detect during inspections. Currently, the conventional method for leak detection is the listening method, which utilizes the characteristic of pipe vibrations transmitted to the ground. During the early morning when ambient noise is low, workers use listening devices to monitor noise levels above the pipes. Based on noise intensity and frequency, they rely on experience to determine if a leak exists. This method is extremely inefficient, requires arduous and strenuous work, and has poor accuracy. Intelligent leak detection methods commonly used include the DMA (Differential Metering and Measurement) method and the leak noise monitoring method. The DMA method calculates the leakage rate based on the difference between inflow and outflow rates in each zone. The leak noise monitoring method relies on equipment to collect and upload noise data, then uses software to analyze noise characteristics to identify leaks. Both methods require the installation of numerous flow meters, water meters, and leak noise monitoring devices, resulting in high investment costs, high failure rates, and difficult maintenance. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a method for monitoring and early warning of leakage in plastic water supply pipelines based on resistance and capacitance. By designing an independent conductive fusion body in the pipeline, and utilizing the correlation characteristics between soil dielectric constant and water content, combined with changes in capacitance and resistance, real-time early warning of leakage is achieved. This solves the problems of high detection rate, high cost, untimely response, and poor stability of existing technologies, and provides an efficient solution for the management of leakage in water supply networks.

[0006] The technical solution adopted in this invention is as follows: A method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance includes the following steps: (1) On the surface of the plastic pipe body, two parallel conductive plastic fusion bodies extending along the length of the pipe are formed by molding process; (2) A resistance and capacitance detection terminal is set at intervals along the pipeline. The resistance and capacitance detection terminal is equipped with three electrodes, which are electrically connected to two independent conductive plastic fusion bodies at that location. The grounding electrode is connected to the earth. It is used to detect the changes in capacitance and resistance between the two conductive plastic fusion bodies and between each conductive plastic fusion body and the earth in real time. (3) After the pipeline installation is completed and put into operation, under the condition of no leakage and no rain interference, each resistance and capacitance detection terminal records the initial capacitance reference value C0 and the initial resistance reference value R0 between the two conductive plastic fusion bodies; the initial capacitance reference values ​​C1, C2 and the initial resistance reference values ​​R1, R2 between each conductive plastic fusion body and the grounding electrode; (4) The resistance and capacitance detection terminal collects the capacitance data between the conductive plastic fused bodies in real time. With resistance data And capacitance data between each conductive plastic fusion body and the grounding electrode. , and resistance data , The system compares the real-time capacitance and resistance values ​​with their respective initial reference values. It sets capacitance warning thresholds ΔC0, ΔC1, and ΔC2, and resistance warning thresholds ΔR0, ΔR1, and ΔR2. When the real-time capacitance continuously increases and the real-time resistance continuously decreases, if the increase in capacitance exceeds the warning threshold and the decrease in resistance exceeds the warning threshold, it is determined that the pipeline is leaking and an alarm is triggered. The system then pushes the leak warning information and approximate location to the remote monitoring platform via the wireless communication module.

[0007] In the above method, in step (1), each conductive plastic fusion body is evenly distributed along the outer circumference of the pipe, with a spacing of 1 / 2 of the circumference of the pipe body. The conductive plastic fusion body is made of conductive plastic, and preferably it is formed by an integral molding process during pipe extrusion molding.

[0008] In step (2), a resistance and capacitance detection terminal is set every 200 to 400 meters, and the grounding electrode is inserted into the ground between 1.5m and 3m.

[0009] In step (4), when leakage occurs, the moisture content of the soil around the leak point increases, and the dielectric constant of the soil increases. This leads to an increase in the capacitance and a decrease in the resistance of the capacitor formed between the two conductive plastic fused bodies. At the same time, it also leads to an increase in the capacitance and a decrease in the resistance between each fused body and the grounding electrode. Since the impact of leakage on the capacitance and resistance of the two sides of the pipeline is different on different sides, it is easier to detect and judge multiple capacitances and resistances in a timely manner.

[0010] A leakage monitoring and early warning device for plastic water supply pipes based on resistance and capacitance includes a plastic pipe with a conductive plastic fusion body, a resistance and capacitance detection terminal, and a remote control platform. A plastic pipe with conductive plastic fusion body is formed on the surface of the plastic pipe body by forming two parallel conductive plastic fusion bodies that extend along the length of the pipe through a molding process. The resistance and capacitance detection terminal includes a resistance and capacitance detection module, a data processing module, an alarm module, and a wireless communication module. The resistance and capacitance detection module has three electrodes, each electrically connected to two independent conductive plastic fusion bodies, and a grounding electrode connected to the earth. It is used to detect the capacitance and insulation resistance between the two conductive plastic fusion bodies and between them and the earth in real time. The data processing module records the initial capacitance reference value C0 and the initial resistance reference value R0 between the two conductive plastic fusion bodies under conditions of no leakage and no rainfall interference; and the initial capacitance reference values ​​C1 and C2 between each conductive plastic fusion body and the grounding electrode. 2、 The system sets initial resistance reference values ​​R1 and R2, compares the real-time capacitance with the initial capacitance reference value, and the real-time resistance with the initial resistance reference value, and sets capacitance warning thresholds ΔC0, ΔC1, and ΔC2, and resistance warning thresholds ΔR0, ΔR1, and ΔR2. When the real-time capacitance continuously increases and the real-time resistance continuously decreases, if the increase in one of the capacitances exceeds the warning threshold and the decrease in one of the resistances exceeds the warning threshold, it is determined to be a pipeline leak, triggering the alarm module to sound an alarm, and pushing the leak warning information and approximate location to the remote monitoring platform through the wireless communication module, thereby realizing real-time leak warning. The remote control platform receives early warning information and location data from each capacitor monitoring terminal, displays them visually, and issues alarms.

[0011] The aforementioned resistance and capacitance detection terminals are installed at intervals along the pipeline.

[0012] The beneficial effects of this invention are: This invention utilizes plastic pipes with conductive plastic fusion bodies and incorporates resistance and capacitance detection terminals. By monitoring changes in resistance and capacitance, it provides timely warnings of pipe leakage events of varying degrees. This helps water supply companies promptly identify, troubleshoot, and repair leaks, achieving real-time and accurate early warning of leakage events in plastic water supply pipes. It reduces leakage detection costs, improves water resource utilization, reduces economic losses for water supply companies, and enhances corporate efficiency. Simultaneously, it contributes technological strength to the development of water resource conservation and water-saving initiatives in my country. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view of the plastic pipe used in this invention; Figure 2 This is a schematic diagram showing the location of the conductive plastic fusion body of the present invention; Figure 3 This is a schematic diagram of the pipeline leakage detection method according to the present invention; Figure 4 This is a schematic diagram of the pipe preparation method according to an embodiment of the present invention; Figure 5 An expert model for the functional relationship between soil moisture content and soil dielectric constant; Among them, 1. Water inside the pipe, 2. Soil with different water content, 3. Plastic pipe body, 4. Conductive plastic fusion body a, 5. Conductive plastic fusion body b, 6. Leakage point, 7. Resistance and capacitance detection terminal; 8. Pipe, 9. Pipe extrusion mold outer tube, 10. Pipe extrusion mold inner tube, 11. Conductive plastic injection port, 12. Pipe plastic injection port. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments.

[0015] Example 1: A method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance, comprising the following steps: (1) On the surface of the plastic pipe body, two parallel conductive plastic fusion bodies extending along the length of the pipe are formed by a molding process: The plastic pipe body is made of insulating material, using common water supply pipe materials such as HDPE and PPR. Its interior is used to transport water with high conductivity. Conductive plastic composite elements are located on the surface of the plastic pipe body, with two sets arranged parallel to each other along the pipe's length. The cross-section is shown below. Figure 1 , Figure 2 As shown; its preparation can be achieved by reprocessing the tube body or by using a one-piece molding process, such as one-piece molding. Figure 4In the extrusion process of manufacturing plastic water supply pipes, the pipe material is extruded between the outer tube 9 and the inner tube 10 of the pipe extrusion die. Conductive plastic injection ports 11 are added to the outer tube 9 of the pipe extrusion die. The injection ports are evenly distributed along the circumference of the die. The number and position of the injection ports are not limited to those shown in the schematic example. Two injection ports are provided. During pipe production, the plastic pipe substrate is heated and melted in the main extruder, and the conductive plastic is heated and melted in the auxiliary extruder. During the extrusion process of pipe 8, the plastic pipe substrate is injected through the pipe plastic injection port 12, and molten conductive plastic is simultaneously injected into the outer surface of the pipe through the conductive plastic injection port 11. The conductive plastic and the pipe substrate are simultaneously formed in the extrusion die. After cooling and solidification, two independent conductive plastic fused bodies are formed on the outer wall surface of the pipe body. Figure 1 Conductive fusion body a4 and conductive fusion body b5 are used. This ensures stable conductivity without affecting the overall pressure-bearing capacity of the pipeline. The conductive plastic fusion body is made of composite materials (such as conductive carbon black-filled polyethylene). The circumferential spacing between adjacent conductive plastic fusion bodies is evenly distributed, with a spacing of 1 / 2 of the pipeline body circumference, ensuring the formation of a stable capacitive structure. Furthermore, by utilizing the principle of capacitance formed between the conductive fusion bodies through the pipeline, water, and soil, the characteristics of capacitance and resistance changes under different humidity soil environments are analyzed to determine whether the pipeline is leaking.

[0016] (2) A resistance and capacitance detection terminal is set at intervals along the pipeline. The resistance and capacitance detection terminal is equipped with three electrodes, which are electrically connected to two independent conductive plastic fusion bodies at that location. The grounding electrode is connected to the earth. It is used to detect the changes in capacitance and insulation resistance between the two conductive plastic fusion bodies and between them and the earth in real time. Resistance and capacitance detection terminals are installed on the plastic pipe body at intervals of 200 to 400 meters.

[0017] (3) After the pipeline installation is completed and put into operation, under the condition of no leakage and no rain interference, each resistance and capacitance detection terminal records the initial capacitance reference value C0, C1, C2 and the initial resistance reference value R0, R1, R2. After the pipeline installation is completed and put into operation, under conditions of no leakage and no rainfall interference, such as Figure 1As shown, the inside of the pipe is filled with highly conductive water (1), and the outside of the pipe is surrounded by soil (2) with varying conductivity and moisture content depending on humidity. Since the pipe itself is an insulator, two plates of a capacitor are formed between conductive plastic fusion body a 4 and conductive plastic fusion body b 5. The medium between the plates is composed of the insulated pipe body, the water inside the pipe, and the surrounding dry soil, forming a capacitor structure with stable initial capacitance and resistance. At this time, the leakage detection and early warning terminal records the initial capacitance reference value C0 and the initial resistance reference value R0. Two plates of a capacitor are formed between conductive plastic fusion body a 4 and the grounding plate, and the medium is composed of a soil medium layer (main medium), forming a capacitor structure with stable initial capacitance and resistance. The initial capacitance reference value C1 and the initial resistance reference value R1 are recorded. Similarly, the initial capacitance reference value and initial resistance reference value of the capacitor formed between conductive plastic fusion body a 5 and the grounding plate are recorded as C2 and R2.

[0018] (4) The resistance and capacitance detection terminal detects the capacitance and resistance data between each capacitor structure in real time, and transmits the real-time capacitance data. , , and real-time resistance data , , The initial capacitance reference values ​​C0, C1, C2 and the initial resistance reference values ​​R0, R1, R2 are compared; respective warning thresholds ΔC0, ΔC1, ΔC2 and ΔR0, ΔR1, ΔR2 are set. During non-rainfall periods, when the real-time capacitance... , , Continuously increasing, real-time resistance data , , When the increase in one of the capacitors exceeds the warning threshold and the decrease in one of the resistors exceeds the warning threshold, it is determined to be a pipeline leak, triggering an alarm. The leak warning information and approximate location are then pushed to the remote monitoring platform via the wireless communication module, achieving real-time leak warning.

[0019] When a leak occurs in the pipe, such as Figure 3 As shown, water inside the pipe leaks into the surrounding soil through seepage point 6 and continues to diffuse outwards, increasing the soil moisture content and forming a roughly ellipsoidal wetted area. As the leakage continues, the wetted area gradually expands, and the soil moisture content around the leak point increases significantly. This is based on the correlation between soil dielectric constant and moisture content (referencing existing expert models such as the TOPP model and the Roth model). Figure 5As shown, referring to existing domestic and international models and curves regarding the relationship between soil dielectric constant and soil moisture content, the dielectric constant increases with increasing soil moisture content. Due to the continuous presence of pipeline leakage and diffusion, the dielectric constant εr of the moist soil surrounding the leakage point gradually increases synchronously.

[0020] According to the capacitance calculation formula: C = εr·S / 4πKd (C - capacitance, εr - dielectric constant, S - area between plates, K - electrostatic constant, d - distance between plates), the dielectric constant εr of the soil around the leak point increases, while the area S of the plates and the distance d between the plates remain unchanged, causing the capacitance of each capacitor to continuously increase from its initial reference value. Simultaneously, because moisture in the moist soil acts as a medium for ion migration, the increased moisture content of the moist soil around the leak point significantly increases the activity of free ions, reducing the insulation resistance between the plates and the ground.

[0021] The warning thresholds ΔC0, ΔC1, ΔC2 and ΔR0, ΔR1, ΔR2 can be calibrated according to the soil type based on the reference values, for example: ΔC0 = 10%~20%×C0, ΔR0 = 10%~20%×R0. When the increase of one of the capacitances exceeds the warning threshold and the decrease of one of the resistances exceeds the warning threshold, it is determined to be a pipeline leak and an alarm is triggered.

[0022] Example 2: A leakage monitoring and early warning device for plastic water supply pipes based on resistance and capacitance, including a plastic pipe with a conductive plastic fusion body, a resistance and capacitance detection terminal, and a remote control platform; A plastic pipe with conductive plastic fusion body is formed on the surface of the plastic pipe body by forming two parallel conductive plastic fusion bodies that extend along the length of the pipe through a molding process. The resistance and capacitance detection terminal includes a resistance and capacitance detection module, a data processing module, an alarm module, and a wireless communication module. The resistance and capacitance detection module has three electrodes, each electrically connected to one of two independent conductive plastic fusion bodies at the specified location. The grounding electrode is connected to the earth. It is used to detect changes in capacitance and insulation resistance between the two fusion bodies and between them and the earth in real time. The data processing module records the initial capacitance reference value C0 and the initial resistance reference value R0 between the two conductive plastic fusion bodies, under conditions of no leakage and no rainfall interference; and the initial capacitance reference values ​​C1 and C2 between each conductive plastic fusion body and the grounding electrode. 2、The system sets initial resistance reference values ​​R1 and R2, compares the real-time capacitance with the initial capacitance reference value, and the real-time resistance with the initial resistance reference value, and sets capacitance warning thresholds ΔC0, ΔC1, and ΔC2, and resistance warning thresholds ΔR0, ΔR1, and ΔR2. When the real-time capacitance continuously increases and the real-time resistance continuously decreases, if the increase in one of the capacitances exceeds the warning threshold and the decrease in one of the resistances exceeds the warning threshold, it is determined to be a pipeline leak, triggering the alarm module to sound an alarm, and pushing the leak warning information and approximate location to the remote monitoring platform through the wireless communication module, thereby realizing real-time leak warning. The remote control platform receives early warning information and location data from each capacitor monitoring terminal, displays them visually, and issues alarms.

[0023] The capacitance detection terminal is installed at intervals along the pipeline.

[0024] The above is a further description of the present invention in conjunction with specific embodiments, and the scope of protection of the present invention is not limited thereto.

Claims

1. A method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance, characterized in that, The steps include the following: (1) On the surface of the plastic pipe body, two parallel conductive plastic fusion bodies extending along the length of the pipe are formed by molding process; (2) A resistance and capacitance detection terminal is set at intervals along the pipeline. The resistance and capacitance detection terminal is equipped with three electrodes, which are electrically connected to two independent conductive plastic fusion bodies at that location. The grounding electrode is connected to the earth. It is used to detect the changes in capacitance and resistance between the two conductive plastic fusion bodies and between each conductive plastic fusion body and the earth in real time. (3) After the pipeline installation is completed and put into operation, under the condition of no leakage and no rain interference, each resistance and capacitance detection terminal records the initial capacitance reference value C0 and the initial resistance reference value R0 between the two conductive plastic fusion bodies; the initial capacitance reference values ​​C1, C2 and the initial resistance reference values ​​R1, R2 between each conductive plastic fusion body and the grounding electrode; (4) The resistance and capacitance detection terminal collects the capacitance data between the conductive plastic fused bodies in real time. With resistance data And capacitance data between each conductive plastic fusion body and the grounding electrode. , and resistance data , The real-time capacitance and resistance values ​​are compared with their respective initial reference values. Set capacitor warning thresholds ΔC0, ΔC1, ΔC2, and resistance warning thresholds ΔR0, ΔR1, ΔR2. When the real-time capacitance continuously increases and the real-time resistance continuously decreases, if the increase in one of the capacitances exceeds the warning threshold and the decrease in one of the resistances exceeds the warning threshold, it is determined that the pipeline is leaking and an alarm is triggered. The leak warning information and approximate location are pushed to the remote monitoring platform through the wireless communication module.

2. The method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance according to claim 1, characterized in that, Step (1) Each conductive plastic fusion body is evenly distributed along the outer perimeter of the pipe, with a spacing of 1 / 2 of the circumference of the pipe body.

3. The method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance according to claim 1, characterized in that, Step (1) The conductive plastic fusion body is made of conductive plastic.

4. The method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance according to claim 1, characterized in that, In step (2), a capacitance detection terminal is set up every 200 to 400 meters.

5. The method for monitoring and early warning of leakage in plastic water supply pipes based on resistance and capacitance according to claim 1, characterized in that, In step (4), when leakage occurs, the water content of the soil around the leakage point increases, the dielectric constant of the soil increases, which will lead to an increase in the capacitance of the capacitor formed between the two conductive plastic fusion bodies and a decrease in resistance; at the same time, it will also lead to an increase in the capacitance between each fusion body and the grounding electrode and a decrease in resistance.

6. A leakage monitoring and early warning device for plastic water supply pipes based on resistance and capacitance, characterized in that, This includes plastic pipes with conductive plastic fusion bodies, resistance and capacitance detection terminals, and remote control platforms; A plastic pipe with conductive plastic fusion body is formed on the surface of the plastic pipe body by forming two parallel conductive plastic fusion bodies that extend along the length of the pipe through a molding process. The resistance and capacitance detection terminal includes a resistance and capacitance detection module, a data processing module, an alarm module, and a wireless communication module. The resistance and capacitance detection module has three electrodes, each electrically connected to two independent conductive plastic fusion bodies, and a grounding electrode connected to the earth. It is used to detect the capacitance and insulation resistance between the two conductive plastic fusion bodies and between them and the earth in real time. The data processing module records the initial capacitance reference value C0 and the initial resistance reference value R0 between the two conductive plastic fusion bodies under conditions of no leakage and no rainfall interference; and the initial capacitance reference values ​​C1 and C2 between each conductive plastic fusion body and the grounding electrode. 2、 The system sets initial resistance reference values ​​R1 and R2, compares the real-time capacitance with the initial capacitance reference value, and the real-time resistance with the initial resistance reference value, and sets capacitance warning thresholds ΔC0, ΔC1, and ΔC2, and resistance warning thresholds ΔR0, ΔR1, and ΔR2. When the real-time capacitance continuously increases and the real-time resistance continuously decreases, if the increase in one of the capacitances exceeds the warning threshold and the decrease in one of the resistances exceeds the warning threshold, it is determined to be a pipeline leak, triggering the alarm module to sound an alarm, and pushing the leak warning information and approximate location to the remote monitoring platform through the wireless communication module, thereby realizing real-time leak warning. The remote control platform receives early warning information and location data from each capacitor monitoring terminal, displays them visually, and issues alarms.

7. The leakage monitoring and early warning device for plastic water supply pipes based on resistance and capacitance according to claim 6, characterized in that, The aforementioned resistance and capacitance detection terminals are installed at intervals along the pipeline.

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