An online monitoring system for municipal pipe network health based on Internet of Things technology

Abstract

The online monitoring system for the health of municipal pipe network based on the Internet of Things technology is characterized by the fact that the outer wall of the municipal drainage pipe network is annularly provided with distributed fiber grating sensors to measure the temperature data of the outer wall of the municipal sewage pipe; the municipal pipe network adopts a segmented control strategy, and a control area is divided every 400-800 meters. The temperature data detected by the distributed fiber grating sensors in each control area is sent to the monitoring center through the optical fiber ring network by the regional switch; the monitoring center determines the leakage status of the municipal drainage pipe network through the temperature data detected by the distributed fiber grating sensors. The system can overcome the many shortcomings and limitations of traditional manual detection methods and traditional sensors, and has accuracy, stability, efficiency, high reliability, easy networking, timeliness, and long-term performance.

Description

Technical Field

[0001] The present invention relates to the field of monitoring of liquid leakage and pipe deformation in municipal pipe networks, and is an online monitoring system for the health of municipal pipe networks based on Internet of Things technology. Background Art

[0002] With the rapid development of my country's economy, especially the accelerated advancement of urbanization, the maintenance and management scope of the existing municipal pipeline network is getting larger and larger, and the requirements for monitoring the municipal pipeline network are getting higher and higher. Although my country has gradually promoted the maintenance and repair of old pipelines in recent years, there are still some weak links. In particular, after heavy rains and rainstorms in a short period of time, some municipal drainage pipes will still have serious disasters such as bursts and bursts. At present, how to monitor the municipal pipeline network is one of the problems that need to be solved urgently.

[0003] Traditionally, the monitoring of municipal pipe networks is mostly done manually, and most of the methods are regular or irregular monitoring. This method is not only inefficient, but also difficult to meet the requirements. As far as the existing monitoring methods are concerned, the health monitoring of municipal pipe networks cannot respond in real time, and it is often not discovered until more serious damage occurs. Traditional methods cannot understand the status of pipeline leakage in real time, which has caused serious disasters such as municipal drainage pipe bursts and even bursts, and are not suitable for the requirements of modern scientific management. Summary of the invention

[0004] The purpose of the present invention is to provide an online monitoring system for the health of municipal pipe networks based on the Internet of Things technology, which takes advantage of the Internet of Things technology and establishes an open system for Internet of Things management and control to achieve the establishment of an efficient, stable and secure Internet of Things system between Internet of Things applications and real devices. Combined with the cognition and stress characteristics of the sewage pipe network, the layout and system construction of multiple sensors in the pipe network, the online health monitoring system can comprehensively monitor the leakage of the pipe network and the stress and strain of the pipeline, evaluate the health of the pipe network throughout its life cycle, and provide timely warnings, maintenance and replacement of related pipe networks to ensure basic people's livelihood.

[0005] The technical solution of the present invention is as follows: an online monitoring system for the health of a municipal pipe network based on the Internet of Things technology, characterized in that a distributed fiber grating sensor is arranged in a ring on the outer wall of the municipal drainage pipe network to measure the temperature data of the outer wall of the municipal sewage pipe; the municipal pipe network adopts a segmented control strategy, and a control area is divided every 400-800 meters. The temperature data detected by the distributed fiber grating sensor in each control area is sent to the monitoring center through the optical fiber ring network by the regional switch; the monitoring center determines the leakage status of the municipal drainage pipe network through the temperature data detected by the distributed fiber grating sensor.

[0006] Furthermore, the distributed optical fiber in the horizontal direction is fixed by the pipe hoisting ear hole or fixed by the dead weight of the soil and fixed with a rubber ring to detect the leakage of the pipe network; the distributed optical fiber in the vertical direction is fixed by the gap of the pipe network interface to detect the leakage of the pipe network and the stress and strain at the interface.

[0007] Furthermore, a coordinator is arranged every 50-80 meters in the control area, and the distributed fiber grating sensors are connected to the regional switch through the coupler and the coordinator. Each coordinator corresponds to one or more couplers, and each coupler corresponds to one or more distributed fiber grating sensors.

[0008] The accuracy, stability and timeliness of distributed fiber Bragg grating sensing technology are just suitable for the actual needs of municipal pipe network leakage monitoring. The present invention uses fiber optic sensing technology to monitor the temperature of the municipal pipe network online during the implementation and operation stages. By interpreting temperature changes and stress and strain, it can be used to monitor the leakage of the pipe network and prevent serious diseases such as pipe surges, bursts, stress and strain in the municipal pipe network in advance to avoid causing more serious losses. The system can overcome the many shortcomings and limitations of traditional manual detection methods and traditional sensors, and has accuracy, stability, efficiency, high reliability, easy networking, timeliness, and long-term performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a system architecture diagram of the present invention.

[0010] Figure 2 This is a schematic diagram of the municipal pipeline network health online detection system - leak monitoring.

[0011] Figure 3 Schematic diagram of the installation of distributed fiber Bragg grating sensors in pipelines. DETAILED DESCRIPTION

[0012] The present invention is further described below by describing a specific embodiment in detail.

[0013] 1. Solution design

[0014] N sets of distributed fiber grating sensors are used: the distributed fiber grating sensors 1 are laid in a ring on the outer wall 2 of the municipal sewage pipe; to ensure the measurement accuracy and density, the distributed fiber grating sensors should be laid along the outer wall of the pipe to measure the temperature change of the outer wall of the municipal sewage pipe. The displacement signal output end and the center wavelength output end of the N sets of distributed fiber grating sensors 1 are connected to the IoT coupler 4 or controller in the area. The collected signal data is edge calculated by the IoT coupler 4 or controller in the area to obtain the changes in the temperature, stress and strain of the outer wall of the municipal sewage pipe.

[0015] 2. On-site sensor installation method

[0016] A. According to the maintenance and management scope of the municipal pipe network to be monitored, determine the number and location of the distributed fiber grating sensors 1, the Internet of Things couplers 4 or controllers in the area; the distributed fiber grating sensors 1 are mainly arranged at the interfaces of the municipal sewage pipe network, important pipe networks, each interface location and where pipe network settlement may occur; the Internet of Things couplers 4 or controllers are arranged one every 50-80 meters; a control area is divided every 400-800 meters, and a regional switch 6 is set in each area. The regional switch 6 is connected to N sets of distributed fiber grating sensors 1 through the coordinator 5, the coupler 4, and the regional switch 6 sends the data detected by the N sets of distributed fiber grating sensors 1 to the monitoring center through the optical fiber ring network 7. Two gateways are arranged in each area, and redundant backup is configured.

[0017] B. During the construction phase, the pre-debugged distributed fiber grating sensor 1 is laid along the wall on the outer wall of the municipal sewage pipe body 2. If there is a special need, it can be laid in a high-density concentrated manner; the horizontal optical fiber can be fixed by the pipe hoisting ear hole or fixed by the soil deadweight and with a rubber ring 3 as backup protection; the vertical optical fiber can be fixed by the gap of the pipe network interface to detect pipe network leakage and stress and strain.

[0018] 3. Data collection, data transmission, and data analysis.

[0019] N distributed fiber grating sensors collect real-time temperature, stress and strain conditions, transmit them to the IoT coupler or controller in the area through optical fiber, and upload them to the superior monitoring center after preliminary processing through edge computing. If the system detects a leak, the system will report the leak location and situation information to the relevant information management center, and notify the maintenance personnel of the relevant ownership units to intervene in advance to deal with the specific leak, so as to ensure the safe and reliable operation of the municipal pipe network.

[0020] Online health detection optimization algorithm:

[0021] First, N fiber Bragg grating sensors are uploaded to the IoT coupler or controller. The entire city's pipe network data is modeled through the municipal sewage pipe network and geographic information system (GIS), and N fiber Bragg grating sensors are used to form N fiber arrays. Based on the system architecture of the IoT, the entire system can be given the ability to timely adjust sensor-related thresholds and underlying data processing.

[0022] When the pipe network is working normally, the surface temperature in different seasons will affect the accuracy of the system. Therefore, the municipal pipe network online monitoring system based on GIS (geographic information system) timely uploads the monitored pipe wall temperature and stress and strain information to the information management center, and adjusts the alarm threshold in time, further increasing the reliability and accuracy of the system. When the temperature difference between the temperature, stress and strain value of the monitoring point and the temperature average value obtained by the nearby fiber grating sensor exceeds the set threshold, the information management system background immediately receives the alarm information, and the sewage pipe network positioning algorithm can be used to determine which fiber array and which section of the pipe network has a problem. This algorithm can timely determine the location of the pipe network leakage point, and the system can be connected with the management platform of the ownership unit to send out work orders in time to carry out timely maintenance of the entire urban pipe network system, thereby ensuring the safe and reliable operation of the municipal pipe network and online monitoring of the entire life cycle.

[0023] The present invention designs the layout of the system architecture by transforming the traditional municipal pipe network monitoring system into a network. By adopting the Internet of Things technology and enabling edge computing technology, local high-reliability control of field control is achieved, which complies with national standards and the development orientation of industry science and technology innovation policies. By laying distributed fiber grating sensors on the outer wall of the municipal pipe network and connecting them to the Internet of Things couplers or controllers in the area, edge computing is performed on the collected data, and effective information is further uploaded to the superior monitoring and management platform in real time, thereby alleviating the processing capacity requirements of the superior data center server. The system architecture is easy to network, and the number of monitoring sensors can be increased or decreased at any time according to actual needs, but there is no programming for the entire system control strategy, which reduces the threshold of operation and maintenance to achieve the purpose of actual engineering needs.

[0024] The relevant sensors for pipeline health detection and fiber grating sensors are connected to the Internet of Things coupler or controller in the area through wireless communication.

[0025] Requirements for sensor deployment in key municipal sewage pipe network areas:

[0026] In key pipeline areas, fiber grating sensors are mainly deployed at the interface positions of the outer wall of the municipal drainage pipeline network. Distributed fiber grating sensors are deployed at each interface position and where pipeline settlement may occur to detect the pipeline conditions throughout the entire life cycle of this section.

[0027] The distributed optical fiber in the horizontal direction is fixed by the pipe hoisting ear hole or fixed by the soil's own weight and fixed with a rubber ring; the distributed optical fiber in the vertical direction is fixed by the gap of the pipe network interface to detect the leakage of the pipe network.

[0028] Monitoring principle of the present invention:

[0029] Distributed temperature measurement principle based on Raman scattering: The distributed fiber optic Raman temperature measurement system measures temperature based on the temperature effect of Raman scattered light. When a laser pulse of a certain energy and width is injected into the optical fiber, it continuously generates backward Raman scattered light while transmitting forward in the optical fiber. The intensity of these backward Raman scattered lights is affected by the temperature of the scattering point of the optical fiber and changes. The temperature information can be calculated in real time by processing the scattered backward Raman light. At the same time, the temperature information can be located according to the transmission speed of light in the optical fiber and the time of the backward light echo.

[0030] When a laser pulse of a certain energy is injected into an optical fiber, Raman scattering occurs at a distance L from the injection point. The relationship between the temperature in the optical fiber and the propagation characteristics of the Raman scattered light can be expressed as:

[0031]

[0032] Where: P S , P AS are the power of Stokes Raman scattered light and Anti-Stokes Raman scattered light respectively; a S , a AS is the loss coefficient of Stokes Raman scattered light and Anti-Stokes Raman scattered light; L is the fiber length from the backscattering point to the detection end; L' is the calibration fiber length placed at a constant temperature T0; h is Planck's constant; k is Boltzmann's constant; Δv is the change in the signal scattering frequency in the optical fiber.

[0033] Based on the principle of pipeline leakage monitoring with distributed optical fiber sensors, during the transportation process of municipal pipelines such as sewage pipes and tap water pipes, there is generally a certain temperature difference between the transported liquid and the outside world. When the temperature of the leaking liquid is different from the outside temperature, the temperature field of the surrounding medium will change as the leaking liquid transfers heat with the surrounding medium and the leaking liquid diffuses. Therefore, the problem of liquid leakage in the pipeline can be converted into the problem of detecting abnormal temperature of the surrounding medium of the pipeline. Figure 2 The following is the monitoring data of the monitoring background, which identifies the on-site conditions based on the sudden change of the temperature curve of the optical cable.

[0034] Based on the principle of distributed fiber grating sensors, the ring-arranged fiber grating sensors can also detect the stress and strain of the pipeline network. By comparing the changes in the central wavelength of the ring optical fiber with the actual pipeline laying conditions, the stress and strain conditions of the corresponding municipal pipeline network can be determined.

[0035] The municipal pipe network health online monitoring system designed by the present invention has the following advantages:

[0036] Accuracy and stability: Compared with traditional manual measurement and traditional sensors, fiber optic sensing technology has higher sensitivity and more accurate measurement results; it is not affected by electromagnetic influences or personal subjective factors, and the measurement results are more stable.

[0037] Efficiency and timeliness: Distributed optical fiber is buried in the outer wall of the municipal pipeline network and connected to the IoT coupler or controller through wireless communication, which can reflect the temperature changes and stress and strain conditions of the pipeline network at any time in real time.

[0038] High reliability and easy networking: Different from traditional methods, after adopting IoT technology, each area is endowed with edge computing capabilities to achieve local high-reliability control of on-site control; through the system architecture of IoT, it is easier to increase or decrease the number of sensor devices and incorporate them into the health detection sub-module.

[0039] Long-term: Compared with short-term manual monitoring, optical fiber has a longer lifespan. It is placed on the outer wall of the pipe network during the construction phase and can be used to monitor the temperature, stress and strain of the outer wall of the municipal pipe network online. It can also monitor and evaluate the health status of the pipe network in the later operation phase.

Claims

1. An online monitoring system for the health of municipal pipe networks based on Internet of Things technology, characterized by Distributed fiber grating sensors are arranged in a ring on the outer wall of the municipal drainage network to measure the temperature data of the outer wall of the municipal sewage pipe. The pre-debugged distributed fiber grating sensors are laid along the wall on the outer wall of the municipal sewage pipe during the construction phase. The municipal pipe network adopts a segmented control strategy, and a control area is divided every 400-800 meters. The regional switch in each control area sends the temperature data detected by the distributed fiber grating sensors in the area to the monitoring center through the optical fiber ring network. The monitoring center determines the leakage status of the municipal drainage network through the temperature data detected by the distributed fiber grating sensors. A coordinator is arranged every 50-80 meters in the control area. The distributed fiber grating sensors are connected to the regional switches through couplers and coordinators. Each coordinator corresponds to one or more couplers, and each coupler corresponds to one or more distributed fiber grating sensors. First, N fiber grating sensors are uploaded to the Internet of Things coupler or controller, and the pipe network data of the entire city is modeled through the municipal sewage pipe network and the geographic information system. N fiber arrays are formed by N fiber grating sensors. When the temperature, When the temperature difference between the stress-strain value and the average temperature obtained by the nearby fiber grating sensor exceeds the set threshold, the information management system background will immediately receive an alarm message, and the sewage pipe network positioning algorithm can be used to determine which fiber array and which section of the pipe network has a problem.

2. The municipal pipe network health online monitoring system according to claim 1 is characterized in that The distributed optical fiber in the horizontal direction is fixed by the pipe hoisting ear hole or fixed by the soil's own weight and fixed with a rubber ring; the distributed optical fiber in the vertical direction is fixed by the gap of the pipe network interface to detect the leakage of the pipe network.

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