CN111896611B - Electromagnetic detection system and detection method for PCCP pipes - Google Patents
Electromagnetic detection system and detection method for PCCP pipes Download PDFInfo
- Publication number
- CN111896611B CN111896611B CN202010618696.XA CN202010618696A CN111896611B CN 111896611 B CN111896611 B CN 111896611B CN 202010618696 A CN202010618696 A CN 202010618696A CN 111896611 B CN111896611 B CN 111896611B
- Authority
- CN
- China
- Prior art keywords
- signal
- magnetic
- excitation
- pccp
- detection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
- G01N27/83—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws by investigating stray magnetic fields
- G01N27/85—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws by investigating stray magnetic fields using magnetographic methods
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
Abstract
本发明涉及PCCP管的电磁检测系统及检测方法，包括：激励源电路用于产生大功率低频交流激励信号；智能监测层设在PCCP管的预应力钢丝层和保护层之间，智能监测层内封装有激励线圈和磁传感器装置，激励线圈用于在激励信号的激发下产生低频交变磁场，预应力钢丝层在交变磁场作用下生成感应磁场，磁传感器装置用于获取PCCP管不同位置的探测信号并传输给信号处理系统；信号处理系统用于对磁探信号进行处理、将磁探信号转化为数字信号、将数字信号传输给主控电脑；主控电脑用于调整激励源电路的参数、根据数字信号的变化情况判断PCCP管的预应力钢丝层是否出现断丝的问题。本发明降低了数据采集基站要求，降低日常监测成本，提高检测效率，无需停水或减压。
The present invention relates to an electromagnetic detection system and detection method for a PCCP pipe, comprising: an excitation source circuit for generating a high-power low-frequency AC excitation signal; an intelligent monitoring layer is arranged between the prestressed steel wire layer and the protective layer of the PCCP pipe, an excitation coil and a magnetic sensor device are encapsulated in the intelligent monitoring layer, the excitation coil is used to generate a low-frequency alternating magnetic field under the excitation of the excitation signal, the prestressed steel wire layer generates an induced magnetic field under the action of the alternating magnetic field, the magnetic sensor device is used to obtain detection signals at different positions of the PCCP pipe and transmit them to a signal processing system; the signal processing system is used to process the magnetic detection signal, convert the magnetic detection signal into a digital signal, and transmit the digital signal to a main control computer; the main control computer is used to adjust the parameters of the excitation source circuit and judge whether the prestressed steel wire layer of the PCCP pipe has a broken wire problem according to the change of the digital signal. The present invention reduces the requirements for data acquisition base stations, reduces daily monitoring costs, improves detection efficiency, and does not require water outage or pressure reduction.
Description
Technical Field
The invention relates to the technical field of intelligent nondestructive testing, in particular to an electromagnetic testing system and method for a PCCP (prestressed concrete cylinder pipe) pipe, which are used for realizing on-line monitoring or periodic investigation of broken wires of a prestressed steel wire layer of the PCCP pipe.
Background
The prestressed steel cylinder concrete pipe (pre-stressed concrete CYLINDER PIPE, PCCP) is a pipe made up by spirally winding high-strength steel wire on the concrete core of steel cylinder and covering with mortar protection layer, and possesses the advantages of long service life and anti-leakage. The method is widely applied to the aspects of long-interval water transmission main lines, pressure inverted siphons, urban water supply engineering, industrial pressurized water transmission lines, power plant circulating water engineering sewer pipes, pressure sewage drainage main pipes and the like. The strength of PCCP depends on the high strength steel wire, which generates uniform prestress on the die and can compensate the tensile stress generated by internal pressure and external load. However, in the running process, various reasons can cause steel wire damage or corrosion, and then fracture occurs, so that the strength of the pipeline is reduced, and finally accidents such as pipe explosion and the like are caused. Therefore, the detection technology for PCCP wire breakage is very important. At present, the abnormality of the PCCP steel wire is mainly evaluated by the reaction changes of sound, magnetism, electricity and the like caused by the abnormality or defect of the internal structure of the material, and the main detection technology comprises a hydrophone monitoring method, a distributed optical fiber monitoring method and an electromagnetic detection method.
The hydrophone monitoring method can be used for monitoring broken wires and leakage, the method is to monitor abnormal acoustic emission signals caused by broken wires or leakage by using a hydrophone, and calculate the abnormal occurrence position according to the time difference of signals received by two adjacent sensors, and the hydrophone monitoring method is realized in a base station mode and an array mode, wherein the difference between the base station mode and the array mode is the sensor spacing and the data transmission mode. The base station type has larger distance and is suitable for rough estimation, the array type is generally used for detailed monitoring, and the base station type adopts a wireless transmission mode and utilizes cable transmission in an array type. The method has the advantages of convenient installation and simple construction, and is suitable for various pipe diameters. The hydrophone monitoring method has the limitations of high operation and maintenance cost, is only suitable for locally monitoring key pipe sections, and can only monitor newly generated broken wires.
The distributed optical fiber monitoring method is mainly used for on-line monitoring of the fracture condition of the steel wire, and is characterized in that sensing optical fibers are paved on the inner wall or the outer wall of the PCCP, acoustic emission signals or stress changes caused by the fracture of the prestressed steel wire are detected, continuous seamless real-time monitoring of more than tens of kilometers can be realized by only one sensing optical cable, the fracture event is accurately positioned, a large number of sensors are not required to be placed, and the distributed optical fiber monitoring method is particularly suitable for long-distance water delivery engineering. Limitations of the distributed optical fiber monitoring method include (1) monitoring only the occurrence of new broken wires and (2) requiring other detection techniques to determine pipeline reference information in advance in order to accurately evaluate the broken wire state.
The basic principles of the two methods are based on acoustic methods, namely acoustic signals or stress changes generated when the steel wires are broken are detected, and the broken wire state of the pipeline before the network is paved can not be obtained, so that the two defects are generated, namely (1) the pipeline is required to be evaluated by an electromagnetic monitoring method before the network is paved, and (2) the acoustic monitoring needs 24 hours to work continuously, otherwise, the broken wire newly generated in the shutdown stage of the pipeline is not detected again, and the daily maintenance cost of the monitoring platform is greatly increased.
Compared with a hydrophone monitoring method and a distributed optical fiber monitoring method, the electromagnetic method detection technology not only can accurately monitor the number and the positions of broken wires in a pipeline, but also can acquire the state of broken wires of the pipeline before the monitoring network is paved.
The electromagnetic method detection technology is mainly applied to broken wire detection of PCCP pipelines, and the far-field current accident/transformer coupling technology (RFEC/TC) and the polar wave detection technology (P-wave) are two electromagnetic method monitoring technologies commonly used in PCCP pipeline detection at present. The far-field traffic detection technique is based on the principle of electromagnetic induction. The steel cylinder or the continuously wound prestressed steel wire corresponds to a coil, and a broken wire or a steel cylinder defect may cause a change in a resistance value or a coil coefficient. The broken wire monitoring is realized by placing a detection platform with an excitation coil and a detection coil into the pipeline, and when the detection platform walks around the pipeline, the excitation coil emits electromagnetic signals which pass through the prestressed steel wire and return to the detection coil. The main control computer records and analyzes the phase and amplitude of the returned electromagnetic signals and the crossing distance and time of the detection vehicle, so that the number and the positions of broken wires are obtained. The polar wave detection technique consists of a transmitting and receiving signal device, wherein the transmitting device generates an electromagnetic field, the receiving device captures an electromagnetic signal passing through the PCCP pipe, and the electromagnetic signal is abnormal due to wire breakage and the like. The number and the positions of broken wires of the monitored pipeline can be accurately obtained through analysis of the abnormal signals. Before detection, the size and the shape of the detected pipeline are calibrated, so that the detection accuracy can be improved. The electromagnetic detection technology is generally realized based on two detection platforms of a push type and a floating type, wherein the push type detection platform is suitable for the following two conditions of pipeline wire breakage risk assessment before formal use of a PCCP pipeline and wire breakage check and overhaul work after water cut of the pipeline, and the floating type platform is suitable for the detection and check of problems such as pipe wall wire breakage, in-pipe siltation and the like under the pipeline operation condition.
For example, the invention patent No. CN104297337B provides a PCCP wire breakage detection method, which comprises the following steps of S1, recording and detecting displacement change conditions through a measuring device during traveling by a detection vehicle, continuously receiving alternating current signals generated by a host machine by a transmitting probe, transmitting corresponding electromagnetic wave signals so as to induce eddy current signals on the PCCP pipe wall, uploading the alternating current signals to a main control computer by the host machine, continuously responding the eddy current signals by the receiving probe to generate voltage signals, S2, repeating the step S1 when the detection vehicle is detected to not reach a preset position, stopping traveling when the detection vehicle is detected to reach the preset position, triggering a data acquisition card, acquiring voltage signals in the receiving probe by the data acquisition card, uploading the voltage signals to the main control computer for display, storage and fault judgment, and S3, restarting traveling, and repeating the steps S1 and S2 until the detection of a required pipe section is completed.
The traditional electromagnetic method detection method has the limitations that (1) a platform can enter the pipeline for detection under the condition of no water or reduced pressure in the PCCP pipeline, and (2) the platform needs to travel in the pipeline completely for obtaining the data of the whole pipeline, and the pipeline can only be detected for tens of kilometers in one day. Therefore, the application range of the traditional electromagnetic method detection method can be greatly influenced, and the daily monitoring of the broken wire state of the PCCP pipe can not be realized and the requirement of frequent detection and maintenance can not be met.
Disclosure of Invention
The invention aims at solving the problems that the traditional electromagnetic method detection method is small in application range and cannot realize daily monitoring of the broken wire state of a PCCP pipe and meet the requirement of frequent detection and maintenance, and provides an electromagnetic detection system and a detection method of the PCCP pipe.
In order to achieve the purpose, the technical scheme provided by the invention is as follows:
The invention relates to an electromagnetic detection system of a PCCP pipe, comprising:
the excitation source circuit is used for generating a high-power low-frequency alternating current excitation signal;
The intelligent monitoring layer is arranged between the prestressed steel wire layer and the protective layer of the PCCP pipe, and an excitation coil and a magnetic sensor device are packaged in the intelligent monitoring layer, wherein the excitation coil is used for generating a low-frequency alternating magnetic field under the excitation of an excitation signal, and the prestressed steel wire layer generates an induction magnetic field under the action of the alternating magnetic field;
the signal processing system is used for processing the magnetic detection signal, converting the magnetic detection signal into a digital signal and transmitting the digital signal to the main control computer;
and the main control computer is used for adjusting parameters of the excitation source circuit and judging whether the prestressed steel wire layer of the PCCP pipe is broken according to the change condition of the digital signal.
Preferably, the magnetic sensor device comprises a plurality of magnetic sensors arranged at different positions of the PCCP pipe so as to acquire magnetic detection signals at different positions of the PCCP pipe, a magnetic sensor array is formed, the magnetic sensors are all provided with communication lines, and the communication lines extend out of the PCCP pipe and are in communication connection with the signal processing system through cables;
The arrangement mode of the magnetic sensor adopts one of a mode of horizontally arranging along the PCCP pipe axis, a mode of obliquely arranging or crossing different pipe wall heights of the PCCP pipe along the horizontal direction, a mode of arranging around the pipe wall of the PCCP pipe or around part of the circumference, a grid arranging mode of combining horizontal arranging and circumferential surrounding arranging, and a grid arranging mode of combining obliquely arranging or crossing arranging and circumferential surrounding arranging.
Preferably, the signal processing system is used for converting magnetic detection signals of different positions of the PCCP pipe detected by each magnetic sensor into a plurality of groups of digital signals, and the main control computer is used for drawing an electromagnetic signal background diagram according to the plurality of groups of digital signals, extracting signal special points by running a magnetic field inversion algorithm and calculating positions and quantity of broken wires.
Preferably, the excitation source circuit includes:
a signal generator for generating a low frequency alternating current signal;
and the current amplifier is used for increasing the power of the low-frequency alternating current signal.
Preferably, the signal processing system includes:
a preamplifier for amplifying the magnetic probe signal;
The filter comprises a band-pass filter and a band-stop filter, wherein the band-pass filter is used for selecting a magnetic detection signal with the same frequency as the excitation signal according to the frequency band of the excitation signal, and eliminating the interference of low-frequency and high-frequency noise;
the phase-locked amplifier is used for further improving the signal-to-noise ratio of the magnetic detection signal according to the frequency and the phase of the excitation source circuit;
The A/D converter is used for converting the magnetic detection signal into a digital signal;
the data acquisition card is used for acquiring digital signals and inputting the digital signals to the main control computer.
Preferably, the exciting coil is a flexible coil wound by a metal wire, a communication line used for connecting an exciting source circuit is arranged on the exciting coil, the communication line extends out of the PCCP pipe and is connected with the exciting source circuit through a cable, and the exciting coil is one of a circular spiral coil, a square spiral coil, a rectangular spiral coil, an elliptic spiral coil and a diamond spiral coil.
Preferably, the excitation source circuit, the signal processing system and the main control computer are all arranged in the ground monitoring base station.
The invention also relates to a detection method of the electromagnetic detection system based on the PCCP pipe, which comprises the following steps:
S1, setting parameters of an excitation source circuit through a main control computer, starting the excitation source circuit to output a high-power low-frequency alternating current excitation signal to an excitation coil, and enabling the excitation coil to generate a low-frequency alternating magnetic field under excitation of the excitation signal;
s2, the prestress steel wire layer generates induction current and generates an induction magnetic field under the action of an alternating magnetic field, the magnetic sensor device obtains the magnetic field intensity of the PCCP tube after the alternating magnetic field and the induction magnetic field are overlapped, and the magnetic field intensity of the different positions is used as detection signals of the positions to be transmitted to the signal processing system;
S3, the signal processing system amplifies the magnetic detection signal, eliminates noise interference, improves signal to noise ratio, converts the magnetic detection signal into a digital signal and transmits the digital signal to the main control computer;
S4, the master control computer judges whether the prestressed steel wire layer of the PCCP pipe is broken according to the change condition of the digital signal.
Preferably, the magnetic sensor device includes a plurality of magnetic sensors disposed at different positions of the PCCP tube, so as to obtain magnetic detection signals at different positions of the PCCP tube, and form a magnetic sensor array, and in step S4, the main control computer further draws an electromagnetic signal background map, operates a magnetic field inversion algorithm to extract signal specific points, and calculates positions and numbers of broken wires according to each digital signal and positions of each magnetic sensor in the magnetic detection array.
Preferably, the signal processing system includes a preamplifier, a filter, a lock-in amplifier, an a/D converter and a data acquisition card, and the specific step of converting the magnetic detection signals at each position in S3 into corresponding digital signals includes:
S3.1, the magnetic sensor is connected with the magnetic detection signals of all the positions into a pre-amplifier, and the magnetic detection signals are amplified;
S3.2, selecting a magnetic detection signal with the same frequency as the alternating current signal generated by the excitation source circuit by using a filter, eliminating the interference of low-frequency and high-frequency noise, and filtering out the influence of a strong interference signal;
s3.3, the phase-locked amplifier further improves the signal-to-noise ratio of the magnetic detection signal according to the frequency and the phase of the excitation source;
s3.4. The A/D converter converts the magnetic detection signal into a digital signal;
s3.5, the data acquisition card acquires digital signals and inputs the digital signals to the main control computer.
The waveform of the exciting current output by the exciting circuit is a periodic waveform or a pulse waveform, the periodic waveform is a sine wave, a triangular wave or a square wave, and the pulse waveform is a pulse waveform formed by one or a plurality of periods of the sine wave, the triangular wave and the square wave.
Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:
1. the exciting coil and the magnetic field sensor array are arranged on the intelligent monitoring layer, and are integrally arranged between the prestressed steel wire layer and the protective layer of the PCCP pipe, and the detection platform does not need to enter the PCCP pipe for detection, so that the method is used for detecting broken wires without stopping water or reducing pressure, and the broken wire condition of the whole PCCP pipe can be detected at the same time when the PCCP pipe works normally, so that a real-time PCCP broken wire monitoring network is formed, and a pre-warning system for broken wires of the PCCP pipe is formed.
2. The detection range of the sensor array in the electromagnetic detection system of the PCCP pipe covers the whole length of the PCCP pipe, magnetic field data of different positions of the PCCP pipe can be collected at one time of detection, and the quantity and the position information of broken wires are obtained through an inversion algorithm, compared with the method that a platform is required to go through the PCCP pipe in the traditional electromagnetic detection technology, the method does not need to work continuously for 24 hours, greatly reduces the requirement on a data acquisition base station, can implement different detection periods and detection modes on the basis of meeting the daily maintenance of different pipe ends according to factors such as PCCP (prestressed concrete cylinder pipe) paving environment, service life and the like, is more flexible in means, can greatly reduce daily monitoring cost, and greatly improves the detection efficiency.
3. Compared with the hydrophone monitoring method and the distributed optical fiber monitoring method, the electromagnetic detection method of the PCCP pipe can realize detection and evaluation of existing broken wires based on the acoustic principle.
Drawings
FIG. 1 is a functional block diagram of an electromagnetic detection system of the PCCP tube of the present invention;
FIG. 2 is a schematic structural view of a PCCP tube;
FIG. 3 is a schematic diagram of the structure of the intelligent monitoring layer in an expanded state;
FIG. 4 is a block diagram of a ground monitoring base station;
Fig. 5 is a line graph of electromagnetic detection results for the case of no wire break and 1 wire break.
The labeling instruction comprises a 1-inner concrete layer, a 2-steel cylinder layer, a 3-outer concrete layer, a 4-prestressed steel wire layer, a 5-intelligent monitoring layer, a 6-protection layer, a 7-excitation coil, an 8-magnetic sensor, a 9-ground monitoring base station and a 10-PCCP pipe.
Detailed Description
The invention will be further understood by reference to the following examples which are given to illustrate the invention but are not intended to limit the scope of the invention.
Referring to fig. 1, the embodiment relates to an electromagnetic detection system of a PCCP pipe, which comprises an excitation source circuit, an intelligent monitoring layer, a signal processing system and a main control computer.
Referring to fig. 1, the excitation source circuit is used for generating a high-power low-frequency alternating current excitation signal, and comprises a signal generator and a current amplifier which are sequentially connected, wherein the signal generator is used for generating the low-frequency alternating current excitation signal, and the current amplifier is used for increasing the power of the excitation signal.
Referring to fig. 2, the structure of the PCCP pipe 10 sequentially comprises an inner concrete layer 1, a steel cylinder layer 2, an outer concrete layer 3, a prestressed steel wire layer 4 and a protective layer 6 from inside to outside, wherein the intelligent monitoring layer 5 is arranged between the prestressed steel wire layer 4 and the protective layer 6 of the PCCP pipe 10, an excitation coil 7 and a magnetic sensor device are packaged in the intelligent monitoring layer 5, the excitation coil 7 is in communication connection with a current amplifier in an excitation source circuit, referring to fig. 3, the excitation coil 7 adopts a flexible coil wound by a metal wire, a communication line for connecting the excitation source circuit is arranged on the excitation coil 7, the communication line extends out of the PCCP pipe and is connected with the excitation source circuit through a cable, the excitation coil 7 adopts one of a circular spiral coil, a square spiral coil, a rectangular spiral coil, an elliptic spiral coil or a diamond spiral coil, the excitation coil is used for generating a low-frequency alternating magnetic field under the excitation of an excitation signal, the prestressed steel wire layer generates an induction magnetic field under the action of the alternating magnetic field, and the magnetic sensor device is used for acquiring alternating magnetic fields and detecting different positions of the PCCP pipe and detecting the alternating magnetic fields and then overlapping the alternating magnetic fields and sending the alternating magnetic fields to different positions as magnetic field intensities for processing magnetic field intensities of the signal transmission systems. Referring to fig. 3, the magnetic sensor device comprises a plurality of magnetic sensors 8 arranged at different positions of the PCCP tube so as to acquire magnetic detection signals at different positions of the PCCP tube, a magnetic sensor array is formed, the magnetic sensors 8 are all provided with communication lines, the communication lines extend out of the PCCP tube and are in communication connection with a signal processing system through cables, the arrangement mode of the magnetic sensors 8 adopts one of a mode of horizontally arranging along the axis of the PCCP tube, a mode of obliquely arranging or crossing the PCCP tube at different tube wall heights along the horizontal direction, a mode of arranging around the PCCP tube wall or around a part of the circumference, a mode of arranging horizontally and circumferentially around the PCCP tube, and a mode of arranging obliquely arranging or crossing the PCCP tube wall and circumferentially around the circumference.
Referring to fig. 1, the signal processing system is in communication connection with the magnetic sensor device, and is used for processing magnetic detection signals of different positions of the PCCP detected by each magnetic sensor, converting the magnetic detection signals into digital signals, transmitting the digital signals to a main control computer, the signal processing system comprises a preamplifier, a filter, a phase-locked amplifier, an A/D converter and a data acquisition card, wherein the preamplifier is used for amplifying the magnetic detection signals, the filter comprises a band-pass filter and a band-stop filter, the band-pass filter is used for selecting magnetic field signals with the same frequency according to an excitation signal frequency band, eliminating interference of low-frequency and high-frequency noise, the band-stop filter is used for filtering out the influence of strong interference signals according to the environment where the PCCP is located, the phase-locked amplifier is used for further improving the signal-to-noise ratio of the magnetic detection signals according to the frequency and the phase of an excitation source circuit, and the data acquisition card is used for acquiring the digital signals and inputting the digital signals to the main control computer.
Referring to fig. 1, the main control computer is respectively connected with the excitation source circuit and the signal processing system in a communication way, and is used for adjusting parameters of the excitation source circuit, judging whether the prestressed steel wire layer of the PCCP pipe has a broken wire problem according to the change condition of digital signals, drawing an electromagnetic signal background diagram according to a plurality of groups of digital signals, extracting signal special points by running a magnetic field inversion algorithm, and calculating the positions and the number of broken wires.
The electromagnetic detection system of the PCCP pipe needs to carry out debugging before detection, and the debugging steps are as follows:
1) The method comprises the steps of arranging a part of an electromagnetic detection system of a PCCP pipe, which is arranged on a ground monitoring base station, in a mobile monitoring vehicle to form a mobile monitoring platform, wherein the mobile monitoring platform comprises an excitation source circuit, a signal processing system, a main control computer and a matched connection circuit thereof;
2) Acquiring electromagnetic detection signals of the non-embedded PCCP pipe steel wires one by one, and acquiring blank signal backgrounds (background signals without wire breakage);
3) When the PCCP pipe is embedded, the connecting line of the intelligent monitoring layer of the PCCP pipe extends to the ground, and the step 3) is repeated when the PCCP pipe formally works, so as to obtain an embedded blank signal background, wherein the background comprises the influence of the PCCP pipe working environment on a magnetic detection signal, and the background is used as a reference background for subsequent electromagnetic detection after the detailed number recording;
4) Referring to figure 4, a ground monitoring base station 9 is established at a proper place, an excitation source circuit, a signal processing system, a main control computer, a corresponding circuit and other matched hardware equipment are installed, the base station is connected with equipment in a monitoring layer 5 of a PCCP pipe 10 of a corresponding pipe section, and the debugging work of the corresponding equipment is completed.
The invention relates to a detection method of an electromagnetic detection system based on a PCCP pipe, which comprises the following steps:
s1, setting parameters of an excitation source circuit through a main control computer, starting the excitation source circuit and outputting a stable high-power low-frequency alternating current excitation signal to an excitation coil, wherein the excitation coil generates a low-frequency alternating magnetic field under excitation of the excitation signal, the excitation signal output by the excitation circuit is excitation current with a periodic waveform or a pulse waveform, the periodic waveform can be a sine wave, a triangular wave or a square wave, and the pulse waveform can be a pulse waveform formed by one or a plurality of periods of the sine wave, the triangular wave and the square wave;
S2, generating induced current by the prestress wire layer under the action of an alternating magnetic field, acquiring magnetic field intensities of alternating magnetic fields and induced magnetic fields of different positions of the PCCP pipe by the magnetic sensor device, and transmitting the magnetic field intensities of the different positions to the signal processing system as detection signals of the different positions;
s3, the signal processing system amplifies the magnetic detection signal, eliminates noise interference, improves signal to noise ratio, converts the magnetic detection signal into a digital signal and transmits the digital signal to the main control computer, and the specific steps comprise:
S3.1, the magnetic sensor is connected with the magnetic detection signals of all the positions into a pre-amplifier, and the magnetic detection signals are amplified;
S3.2, selecting a magnetic detection signal with the same frequency as the alternating current signal generated by the excitation source circuit by using a filter, eliminating the interference of low-frequency and high-frequency noise, and filtering out the influence of a strong interference signal;
s3.3, the phase-locked amplifier further improves the signal-to-noise ratio of the magnetic detection signal according to the frequency and the phase of the excitation source;
s3.4. The A/D converter converts the magnetic detection signal into a digital signal;
S3.5, the data acquisition card acquires digital signals and inputs the digital signals to the main control computer;
S4, the main control computer judges whether the wire breaks according to the change condition of the digital signals, draws an electromagnetic signal background diagram according to the digital signals and the positions of the magnetic sensors in the magnetic detection array, operates a magnetic field inversion algorithm to extract signal special points, and calculates the positions and the number of the wire breaks.
The electromagnetic detection system of the PCCP pipe can perform on-line monitoring on the PCCP pipe, namely an excitation signal is continuously generated when the coil is excited for 24 hours, the magnetic sensor device senses a detection signal continuously for 24 hours, further on-line monitoring is achieved, when a prestress steel wire layer breaks at a certain moment, a main control computer timely feeds back the positions and the number of broken wires, and accordingly PCCP pipe safety can be conveniently evaluated timely and maintenance work is carried out on the found dangerous pipe section.
The electromagnetic detection system of the PCCP pipe can also detect the PCCP pipe periodically, and the detection process comprises the steps of making different daily detection periods according to the service life, the working environment and the early wire breakage detection condition of the PCCP pipe, making different pipe sections, ensuring the normal work of the PCCP pipe, monitoring the safety of the PCCP pipe, carrying out electromagnetic detection on the corresponding pipe sections periodically according to the made detection periods, namely, steps S2-S4, recording detection data, evaluating the safety of the PCCP pipe, and carrying out maintenance work on dangerous pipe sections.
In the embodiment, the model number of the detected PCCP tube is PCCPDE-1400, the size of the exciting coil 7 is 23cm in inner diameter and 30cm in outer diameter, the number of turns of the coil is 500, and the exciting coil 7 is positioned at the center of the PCCP tube axis. The excitation source circuit is set to have an excitation frequency of 73Hz, an output waveform is a sine wave, the effective value of current output is 0.8A, the excitation circuit is kept to stably and continuously output, and the coil is driven to generate an alternating magnetic field. The magnetic sensor device is characterized in that the magnetic sensor device is arranged on the other side of the PCCP tube opposite to the exciting coil 7, the magnetic detector is a tunnel magneto-resistance sensor (TMR), the magnetic sensor is horizontally and uniformly arranged along the axial direction of the PCCP tube, the distance between the adjacent sensors is 10cm, the sensors are powered by an 8V direct current power supply in parallel, a data output line is connected into a phase-locked amplifier, the sensitivity of the phase-locked amplifier is 200, the integration time is 500ms, the data collected by each magnetic sensor is further drawn into a graph by a computer, the graph is shown in fig. 5, which shows the electromagnetic detection results under the conditions of no broken wire and 1 broken wire, the position of the broken wire is a horizontal coordinate 0 point, and a specific peak exists at the position of the broken wire in the graph, so that the electromagnetic detection of the broken wire is realized.
The present invention has been described in detail with reference to the embodiments, but the description is only the preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. All equivalent changes and modifications within the scope of the present invention should be considered as falling within the scope of the present invention.
Claims (7)
1. An electromagnetic detection system of a PCCP pipe, characterized in that it comprises:
the excitation source circuit is used for generating a high-power low-frequency alternating current excitation signal;
The intelligent monitoring layer is arranged between the prestressed steel wire layer and the protective layer of the PCCP pipe, and an excitation coil and a magnetic sensor device are packaged in the intelligent monitoring layer, wherein the excitation coil is used for generating a low-frequency alternating magnetic field under the excitation of an excitation signal, and the prestressed steel wire layer generates an induction magnetic field under the action of the alternating magnetic field;
the magnetic sensor device comprises a plurality of magnetic sensors which are arranged at different positions of the PCCP pipe so as to acquire magnetic detection signals at different positions of the PCCP pipe, a magnetic sensor array is formed, the magnetic sensors are all provided with communication lines, and the communication lines extend out of the PCCP pipe and are in communication connection with the signal processing system through cables;
The arrangement mode of the magnetic sensor adopts one of a mode of horizontal placement along the PCCP pipe axis, a mode of oblique placement or cross placement at different pipe wall heights of the PCCP pipe along the horizontal direction, a mode of placement around the pipe wall of the PCCP pipe or around part of the circumference, a grid placement mode of combining horizontal placement and circumferential placement, and a grid placement mode of combining oblique placement or cross placement and circumferential placement;
The signal processing system is used for processing the magnetic detection signals, converting the magnetic detection signals of different positions of the PCCP pipe detected by each magnetic sensor into a plurality of groups of digital signals and transmitting the digital signals to the main control computer;
the main control computer is used for adjusting parameters of the excitation source circuit, judging whether the prestressed steel wire layer of the PCCP pipe has the problem of wire breakage or not according to the change condition of the digital signals, drawing an electromagnetic signal background diagram according to a plurality of groups of digital signals, operating a magnetic field inversion algorithm to extract signal special points and calculating the positions and the number of the wire breakage.
2. The electromagnetic detection system of the PCCP tube as recited in claim 1, wherein the excitation source circuit comprises:
a signal generator for generating a low frequency alternating current signal;
and the current amplifier is used for increasing the power of the low-frequency alternating current signal.
3. The electromagnetic detection system of a PCCP tube as in claim 1, wherein the signal processing system comprises:
a preamplifier for amplifying the magnetic probe signal;
The filter comprises a band-pass filter and a band-stop filter, wherein the band-pass filter is used for selecting a magnetic detection signal with the same frequency as the excitation signal according to the frequency band of the excitation signal, and eliminating the interference of low-frequency and high-frequency noise;
the phase-locked amplifier is used for further improving the signal-to-noise ratio of the magnetic detection signal according to the frequency and the phase of the excitation source circuit;
The A/D converter is used for converting the magnetic detection signal into a digital signal;
the data acquisition card is used for acquiring digital signals and inputting the digital signals to the main control computer.
4. The electromagnetic detection system of the PCCP pipe according to claim 1, wherein the exciting coil is a flexible coil wound by a metal wire, a communication line for connecting an exciting source circuit is arranged on the exciting coil, the communication line extends out of the PCCP pipe and is connected with the exciting source circuit through a cable, and the exciting coil is one of a circular spiral coil, a square spiral coil, a rectangular spiral coil, an elliptical spiral coil or a diamond spiral coil.
5. The electromagnetic detection system of the PCCP pipe as in claim 1, wherein the excitation source circuit, the signal processing system and the main control computer are all arranged in the ground monitoring base station.
6. A detection method of an electromagnetic detection system based on the PCCP pipe as claimed in claim 1, characterized in that it comprises the following steps:
S1, setting parameters of an excitation source circuit through a main control computer, starting the excitation source circuit to output a high-power low-frequency alternating current excitation signal to an excitation coil, and enabling the excitation coil to generate a low-frequency alternating magnetic field under excitation of the excitation signal;
s2, the prestress steel wire layer generates induction current and generates an induction magnetic field under the action of an alternating magnetic field, the magnetic sensor device obtains the magnetic field intensity of the PCCP tube after the alternating magnetic field and the induction magnetic field are overlapped, and the magnetic field intensity of the different positions is used as detection signals of the positions to be transmitted to the signal processing system;
the magnetic sensor device comprises a plurality of magnetic sensors which are arranged at different positions of the PCCP pipe so as to acquire magnetic detection signals at different positions of the PCCP pipe and form a magnetic sensor array;
S3, the signal processing system amplifies the magnetic detection signal, eliminates noise interference, improves signal to noise ratio, converts the magnetic detection signal into a digital signal and transmits the digital signal to the main control computer;
S4, the master control computer judges whether the prestressed wire layer of the PCCP pipe has the problem of wire breakage according to the change condition of the digital signals, draws an electromagnetic signal background diagram according to the digital signals and the positions of the magnetic sensors in the magnetic detection array, operates a magnetic field inversion algorithm to extract signal special points, and calculates the positions and the number of the wire breakage.
7. The method for detecting the electromagnetic detection system based on the PCCP tube according to claim 6, wherein the signal processing system comprises a preamplifier, a filter, a lock-in amplifier, an A/D converter and a data acquisition card, and the specific step of converting the magnetic detection signals at each position into corresponding digital signals in S3 comprises the following steps:
s3.1, the magnetic sensor is connected with the magnetic detection signals of all the positions into a pre-amplifier to amplify the magnetic detection signals;
s3.2, selecting a magnetic detection signal with the same frequency as the alternating current signal generated by the excitation source circuit by using a filter, eliminating the interference of low-frequency and high-frequency noise, and filtering out the influence of a strong interference signal;
S3.3, the phase-locked amplifier further improves the signal-to-noise ratio of the magnetic detection signal according to the frequency and the phase of the excitation source;
S3.4, converting the magnetic detection signal into a digital signal by the A/D converter;
S3.5, the data acquisition card acquires digital signals and inputs the digital signals to the main control computer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010618696.XA CN111896611B (en) | 2020-06-30 | 2020-06-30 | Electromagnetic detection system and detection method for PCCP pipes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010618696.XA CN111896611B (en) | 2020-06-30 | 2020-06-30 | Electromagnetic detection system and detection method for PCCP pipes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111896611A CN111896611A (en) | 2020-11-06 |
| CN111896611B true CN111896611B (en) | 2025-02-11 |
Family
ID=73191307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010618696.XA Active CN111896611B (en) | 2020-06-30 | 2020-06-30 | Electromagnetic detection system and detection method for PCCP pipes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111896611B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112946062B (en) * | 2021-02-02 | 2022-02-01 | 北京湜沅科技有限公司 | PCCP pipeline broken wire inspection method based on electromagnetic wave and sound template library algorithm |
| CN116299720B (en) * | 2023-05-16 | 2024-04-26 | 北京市水科学技术研究院 | PCCP broken wire multichannel electromagnetic detection equipment |
| CN116299721B (en) * | 2023-05-16 | 2024-07-23 | 北京市水科学技术研究院 | PCCP broken wire multichannel electromagnetic detection system and method |
| CN120721252A (en) * | 2025-08-28 | 2025-09-30 | 杭州健而控科技有限公司 | PCCP pipe wire breakage advance warning device and method based on absolute stress monitoring |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109073599A (en) * | 2016-04-22 | 2018-12-21 | 通用电气石油和天然气英国有限公司 | Failure detection in hose and reinforced hose |
| CN110346838A (en) * | 2019-06-18 | 2019-10-18 | 天津精仪精测科技有限公司 | A kind of PCCP pipe fracture of wire detection device based on orthogonal electromagnetic principle |
| CN212301419U (en) * | 2020-06-30 | 2021-01-05 | 杭州量泓科技有限公司 | A kind of electromagnetic detection system of PCCP tube |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3833971A4 (en) * | 2018-08-08 | 2022-05-04 | Pure Technologies Ltd. | Method and apparatus to detect flaws in metallic pipe |
| CN109884179B (en) * | 2019-04-10 | 2021-04-23 | 中国水利水电科学研究院 | A method and device for detecting the state of a prestressed concrete cylinder tube |
| CN110018228B (en) * | 2019-04-26 | 2024-02-27 | 中国水利水电科学研究院 | System, method and device for detecting broken wire position of embedded PCCP (prestressed concrete cylinder pipe) |
-
2020
- 2020-06-30 CN CN202010618696.XA patent/CN111896611B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109073599A (en) * | 2016-04-22 | 2018-12-21 | 通用电气石油和天然气英国有限公司 | Failure detection in hose and reinforced hose |
| CN110346838A (en) * | 2019-06-18 | 2019-10-18 | 天津精仪精测科技有限公司 | A kind of PCCP pipe fracture of wire detection device based on orthogonal electromagnetic principle |
| CN212301419U (en) * | 2020-06-30 | 2021-01-05 | 杭州量泓科技有限公司 | A kind of electromagnetic detection system of PCCP tube |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111896611A (en) | 2020-11-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111896611B (en) | Electromagnetic detection system and detection method for PCCP pipes | |
| CN101672429A (en) | Petroleum pipeline detecting system | |
| CN101603630A (en) | The monitoring pipeline vibration system and method | |
| KR20180063042A (en) | Detection and monitoring of changes in metal structures using multi-mode acoustic signals | |
| CN102841143B (en) | Method for detecting corrosion of grounded grid circular steel bar based on lateral loading of piezoelectric sensors | |
| CN204678066U (en) | Optical fiber distributed type heat distribution pipe network monitoring system | |
| CN110346838A (en) | A kind of PCCP pipe fracture of wire detection device based on orthogonal electromagnetic principle | |
| CN104280453A (en) | System applied to detection of broken PCCP (Prestressed Concrete Cylinder Pipe) steel wires | |
| CN100399019C (en) | Underground Pipeline Corrosion and Leakage Intelligent Online Detection System | |
| CN109406631B (en) | Parallel steel wire sling detection device and method | |
| JP2002039810A (en) | Civil engineering / construction structure condition inspection method and system, and sensor-integrated device used therefor | |
| AU2022301223A9 (en) | Power transmission line fault positioning method, recording medium, and data processing apparatus | |
| CN115127034A (en) | An intelligent management system for pipe network operation safety | |
| CN116500124A (en) | Inhaul cable defect detection method and device based on electromagnetic tomography technology | |
| CN212301419U (en) | A kind of electromagnetic detection system of PCCP tube | |
| CN104564023B (en) | Non-contact type high-precision array electromagnetic thickness tool | |
| CN113884566B (en) | Positioning method of pipeline weld | |
| CN111664364B (en) | An online monitoring system and monitoring method for buried pipeline leakage | |
| CN202402950U (en) | Portable pipe corrosion and leakage on-site detecting device | |
| US20180209787A1 (en) | Method for detecting change in underground environment by using magnetic induction, detection sensor and detection system | |
| CN110617401A (en) | Intelligent pipeline drainage system | |
| CN107664662A (en) | Long range rail failure detector | |
| CN104359970A (en) | PCCP (prestressed concrete cylinder pipe) steel wire breaking detection main unit | |
| CN114061500A (en) | Dynamic monitoring system for pipeline deformation instability based on acoustic emission technology | |
| CN210831449U (en) | Pipeline drainage system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |