A pressure water pipeline leakage detection / monitoring system, method and medium

Abstract

The present invention provides a pressure water pipeline leakage detection / monitoring system, method and medium, including: a sensor device for sensing the leakage noise of the water pipeline; a data acquisition module for receiving the leakage noise sensed by the sensor device and converting it into a leakage noise digital signal; a central server receives the leakage noise digital signal fed back by the data acquisition module, analyzes the received leakage noise digital signal, determines whether the water pipeline is leaking through calculation and analysis, and locates the position of the leakage noise source according to the analysis result, that is, determines the position of the leakage point, and calculates the leakage amount at the leakage point; at the same time, the central server sends a control instruction to the data acquisition module to detect or monitor the leakage of the pressure water pipeline. The present invention detects / monitors the leakage noise of the pipeline, uses the source tracing method to accurately locate the position of the noise source, and calculates the noise source intensity, so as to achieve the purpose of leakage detection / monitoring.

Description

Technical Field

[0001] The present invention relates to the field of safety detection / monitoring of pressure water pipelines, and in particular to a source tracing method, system and medium for leakage detection / monitoring of pressure water pipelines. Background Art

[0002] Water resources are an important strategic resource for a country. In order to ensure water supply for industrial and agricultural production and urban residents, and to ensure the sustainable development of the economy and society, my country has built a large number of water diversion projects, including the Middle and Eastern Lines (Phase I) of the South-to-North Water Diversion Project, the Luan River to Tianjin Project, the Dongshen Water Supply Project, and the Xijiang Water Supply Project. The large-scale inter-basin water diversion projects under construction and planned include the West and Eastern Lines (Phase II) of the South-to-North Water Diversion Project, the Han River to Wei River Diversion Project, the Song River (Huajiang River) to Changchun River Diversion Project, and the Chao River to Liao River Diversion Project. Large-scale pressure water pipelines are an important part of these facilities. On the other hand, in terms of urban domestic water supply, the tap water network is an important infrastructure that safely and reliably delivers domestic water to thousands of households, covering all towns and villages in my country.

[0003] At present, leakage is common in my country, whether it is long-distance large-scale pressure water pipelines or urban tap water pipe networks. Leakage not only wastes precious water resources, but also causes serious accidents such as ground collapse and pipe bursts, resulting in huge property losses and even casualties, affecting social harmony and stability. According to statistics, the leakage rate of urban tap water pipe networks in my country is as high as 15% to 20%, which is an astonishing loss.

[0004] At present, the main method for large-scale buried pressure water pipelines at home and abroad is to find leakage and other defects through regular water outage inspection and maintenance to prevent the occurrence of pipe burst accidents caused by harmful concentrated leakage. Due to the long interval between water outage inspection and maintenance of large-scale buried pressure water pipelines (usually once a year) and the short maintenance period, the water outage inspection and maintenance method cannot effectively prevent the occurrence of pipe burst caused by harmful concentrated leakage. Although some newly built or under-construction buried pressure water pipelines have added pressure monitoring and flow monitoring measures, the pressure and flow monitoring sensitivity is low, and can only detect accidents such as serious pipeline leakage, but cannot detect smaller leakage. Secondly, due to the long distance of the water pipeline, a detection point is often set up for several kilometers or even longer, and it can only be found that the leakage occurs in a certain section of the pipeline, and it is impossible to accurately locate it, making it difficult to play the role of timely detection of the leakage point.

[0005] At present, leakage detection of urban water pipe networks mainly relies on manual leakage detection with a leak detector to find the leakage point. The working principle of the leak detector is based on the following phenomenon: when the pipe is damaged, the water in the pipe is sprayed out of the pipe under pressure, producing a whistling sound. When the pipe is buried shallowly and the leakage is serious, this leakage noise can be heard by placing a microphone close to the ground in a relatively quiet environment. Due to the large amount of traffic in cities, the noisy environment, the crisscrossing of various pipe networks, and the different buried depths, the leak detector can only find some shallowly buried and leaking leakage points. The detection sensitivity, positioning accuracy and anti-interference ability cannot meet the needs and cannot fundamentally solve the problem.

[0006] In summary, in my country, there is currently a lack of effective detection / monitoring means for both the hazardous concentrated leakage of long-distance large-scale pressure water pipelines and the leakage of urban tap water pipe networks. A high-precision, high-sensitivity, high-reliability and high-efficiency detection / monitoring method and system is urgently needed. Summary of the invention

[0007] In view of the defects in the prior art, the purpose of the present invention is to provide a source tracing method for leakage detection / monitoring of pressure water pipelines and its system and medium.

[0008] The first aspect of the present invention provides a pressure water pipeline leakage detection / monitoring system, comprising:

[0009] A sensor device arranged along the extension direction of the water pipeline, the sensor device is used to sense the leakage noise of the water pipeline;

[0010] A data acquisition module, the data acquisition module is used to receive the leakage noise sensed by the sensor device and convert it into a leakage noise digital signal;

[0011] The central server receives the leakage noise digital signal fed back by the data acquisition module, analyzes the received leakage noise digital signal, determines whether the water pipeline is leaking through calculation and analysis, and locates the leakage noise source according to the analysis result, that is, determines the location of the leakage point, and calculates the leakage amount at the leakage point, so as to detect or monitor the leakage of the pressure water pipeline; at the same time, the central server sends a control instruction to the data acquisition module.

[0012] Preferably, the pressure water pipeline leakage detection / monitoring system comprises:

[0013] A data transmission module, the data transmission module is used to transmit the leakage noise signal digitized by the data acquisition module to the central server according to instructions, and receive control instructions output by the central server;

[0014] A data publishing module, wherein the data publishing module is used to publish the analysis results of the central server through a display and / or a terminal device.

[0015] Preferably, the sensing device comprises:

[0016] A plurality of mobile bases are arranged on the ground and along the extending direction of the water pipeline, each of the mobile bases is provided with a vibration sensor, so that each of the sensors is tightly coupled with the ground through the mobile base;

[0017] A soundproof cover is arranged outside the mobile base, and the vibration sensor is located inside the soundproof cover, and the soundproof cover blocks external environmental noise;

[0018] A traction belt, through which a plurality of movable bases are sequentially connected to form a linear array of sensors;

[0019] A traction device is connected to one end of the traction belt and can drive the traction belt to move along the ground under traction, thereby driving a plurality of movable bases and the vibration sensor to move as a whole.

[0020] Preferably, the linear array of sensors is connected to the data acquisition module via a cable.

[0021] Preferably, the sensing device is a distributed acoustic sensor optical fiber;

[0022] The distributed acoustic sensor optical fiber is arranged inside the water pipeline along the pipeline axis, and one end of the distributed acoustic sensor optical fiber extends to the outside of the water pipeline. The distributed acoustic sensor optical fiber is used to transmit optical signals and sense vibrations at the same time.

[0023] A second aspect of the present invention provides a pressure water pipeline leakage detection / monitoring method, the method adopts a source tracing method, comprising:

[0024] S1: a sensor device is arranged along the extension direction of the water pipeline to sense the leakage noise of the water pipeline, and a central server is used to analyze the received leakage noise digital signal, and it is determined through calculation and analysis whether the water pipeline is leaking, and the position of the leakage noise source is located according to the analysis result, so as to determine the leakage point;

[0025] S2: Calculate the noise source intensity at the leakage point using the central server, and determine the leakage degree according to the noise source intensity;

[0026] S3: The steady-state random process method is used to analyze leakage noise data to improve the accuracy of leakage point location inference and the stability of the results.

[0027] Optionally, the S1 includes:

[0028] Assume that N vibration sensors are arranged along the extension direction of the water pipeline and are i , i = 1, 2, 3, ... N, the coordinates of the N vibration sensors are x i , i = 1, 2, 3, ... N, the signals received by the N vibration sensors are s i (t), i = 1, 2, 3, ... N, the leakage noise source is located at x = x0, that is, the leakage point is located at x = x0;

[0029] Assume that the noise signal emitted by the leakage noise source is w(t), its spectrum is W(f), and the signals received by any two sensors m and n are s m (t) and s n (t), whose Fourier spectra are S m (f) and S n (f), and let v represent the propagation speed of noise along the medium, f represent the frequency, π represent the circumference of a circle, j represent the imaginary unit, and Exp() represent the exponential function; then:

[0030] s m (t) = w(t-(x m -x0) / v) ①

[0031] and n (t) = w(t-(x n -x0) / v)①' Its Fourier spectra are:

[0032] S m (f) = W(f) * Exp(-j2πf((x m -x0) / v)) ②

[0033] and S n (f)=W(f) * Exp(-j2πf((x n -x0) / v))②'then the signal s m (t) and s n The cross spectrum of (t) is:

[0034]

[0035] Above The difference in propagation distance (x n -x m ) caused by the signal phase lag, which is caused by the distance difference (x n -x m) and propagation speed (v) are uniquely determined; according to equations ③ and ④, if the first sensor p1 is taken as the reference point, the values ​​of each sensor (p i , i=1,2,3,...N)signal (s i The cross spectrum of the signal of sensor p1 (s1(t)) and the signal of sensor p1 (s1(t)) is obtained:

[0036]

[0037] In the above formula, |W(f)| 2 ≥0, (x1-x i ) is a known quantity, and the propagation velocity (v) of the leakage noise is obtained by the following method:

[0038] Assume a velocity v k , calculated at speed v k The phase difference between the next i-th sensor and the first sensor is:

[0039]

[0040] Then from the cross spectrum S 1,i The phase angle of (f) is eliminated This is equivalent to propagating the position of sensor p1 to p i The leakage noise signal at the position of p i Trace back to p1;

[0041] Superimpose the traced signals and calculate the standardized superposition energy of the signals:

[0042]

[0043] If the speed v used for tracing k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the speed v used for tracing k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k will become relatively smaller;

[0044] The propagation velocity of the leakage noise is obtained using the following velocity scanning method:

[0045] Determine the minimum propagation velocity V min and the maximum propagation speed V max , and then increase the speed by a certain increment of δv, so that the propagation speed is V min Increase to V max , calculate the standardized superposition energy E corresponding to different propagation speeds according to formula ⑦ k(f), find the maximum superposition energy E 0 (f) The corresponding propagation speed V o It is the actual propagation speed of leakage noise;

[0046] When the propagation speed V is obtained o Then, according to the above formula ②, for all N sensors (p i , i=1,2,3,...N) data, assuming that the location of the leakage noise source is x k , the calculated signal is x k Propagate to sensor p i Phase difference caused by position:

[0047]

[0048] Then from the sensor p i The spectrum S i The phase angle of (f) is eliminated It is equivalent to putting the sensor p i The leakage noise signal at the position is from p i Trace back to x k , and then calculate the normalized superposition energy of the signal:

[0049]

[0050] If the assumed leakage point position x k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the assumed leak point position x k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k will become relatively smaller;

[0051] The following field source scanning method is used to determine the location of the leakage noise source, that is, the location of the leakage point:

[0052] Determine the minimum leakage noise source location X min and the maximum leakage noise source position X max , and then with a certain position increment δx, the leakage noise source position is changed from X min Change to X max , use formula ⑨ to calculate the assumed different leakage noise source positions x k The corresponding normalized superposition energy E k (f), find the maximum superposition energy E 0 (f) The corresponding leakage noise source position x 0 That is the actual location of the leakage point (x0).

[0053] Optionally, the S2 includes:

[0054] Let T be the length of the received signal, sensor p i , i=1,2,3,...N received leakage noise s i The average amplitude of (t) A i , i=1,2,3,...N is expressed as:

[0055]

[0056] The signal amplitude A of N sensors in formula ⑩ i , i = 1, 2, 3, ... N and the position x of N sensors i , i=1,2,3,...N, establish the relationship between the leakage noise intensity A and the position x A=g(x), then substitute the coordinates of the leakage point position x0, and obtain the amplitude of the leakage noise at the leakage point A0=g(x0), and then obtain the relationship between the leakage noise amplitude and the leakage degree I=Q(A) through calibration experiments, and the severity of the leakage is obtained as I0=Q(A0).

[0057] Optionally, S3 is performed according to the following steps:

[0058] S31: Divide the monitoring data obtained by N sensors into M segments of equal length to obtain a set of monitoring data [s i m ], subscript i = 1, 2, 3, ... N represents the sensor number, [s i m ] The superscript m=1,2,3,...M represents the data segment number;

[0059] S32: Taking the first sensor p1 as the reference point, use the first segment data to obtain the values ​​of the remaining sensors (p i , i=1,2,3,...N)signal (s i 1 (t), i = 1, 2, 3, ... N) and the signal of sensor p1 (s1 1 The cross spectrum (S 1 i,1 (f));

[0060] S33: Calculate the remaining sensors (p i , i=1,2,3,...N)signal (s i 2 (t), i = 1, 2, 3, ... N) and the signal of sensor p1 (s1 2 The cross spectrum (S 2 i,1 (f));

[0061] S34: According to the above process of S33, the cross spectrum (S m i,1 (f), m = 1, 2, 3, ... M);

[0062] S35: Obtain the ensemble average of the cross-spectrum:

[0063] S av i,1 (f)=(Σ(S m i,1 (f), m = 1, 2, 3, ... M)) / M;

[0064] S36: The cross-spectrum ensemble average S av i,1 (f) Replace the cross spectrum S in equation ⑦ i,1 (f), obtaining the propagation velocity of the leakage noise by using the velocity scanning method;

[0065] S37: For each segment of data, calculate the superposition energy E according to formula 9 k,m (f), superscript k = 1, 2, 3, ... represents the field source scanning sequence number, superscript m = 1, 2, 3, ... M represents the data segment sequence number;

[0066] S38: Find the ensemble average of the superposition energy:

[0067] E k,av (f)=(Σ(E k,m (f), m=1,2,3,...M)) / M

[0068] S39: Find out the field source position corresponding to the maximum superposition energy, which is the position of the leakage point.

[0069] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned pressure water pipeline leakage detection / monitoring method is implemented.

[0070] The basic principle of the present invention is: when a pressure water pipeline is damaged, the water in the pipeline will spray out from the broken part of the pipeline under the action of pressure, causing the pipeline to vibrate and produce whistling. This vibration and whistling are usually called leakage noise. The location of the noise source is the location of the leakage point, and the intensity of the noise source reflects the severity of the leakage. The source tracing method for leakage detection / monitoring of pressure water pipelines of the present invention is based on this phenomenon. By detecting / monitoring the leakage noise of the pipeline, the location of the noise source is located by the source tracing method, and the noise source intensity is calculated to achieve the purpose of leakage detection / monitoring.

[0071] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0072] The above system of the present invention utilizes the phenomenon that when a pressure water pipeline leaks, it produces whistling and causes pipeline vibration. Based on theoretical analysis and experimental research, it proposes to form a sensor array through multiple sensor devices, use the source tracing method to accurately determine the location of the leakage point, evaluate the leakage amount, and introduce the steady-state random process theory into data analysis, which greatly improves the sensitivity and anti-interference ability of the method and makes due contributions to water supply safety. The above system can involve inter-basin water transfer projects, water conservancy and hydropower projects, and municipal tap water network projects, and is also suitable for the safety monitoring of pressure pipelines or pressure vessels that transport or store other liquid or gaseous substances in industries such as petrochemicals.

[0073] The above system of the present invention is suitable for being made into a flexible and portable detection system, which can be deployed and detected at any time as needed, and can also be made into a fixed monitoring system to monitor a certain pipeline for a long time.

[0074] The above method of the present invention is based on the theory of steady-state random processes and greatly improves the detection sensitivity and anti-interference ability by superimposing long-term detection / monitoring data.

[0075] The above method of the present invention traces and superimposes the data of multiple sensor devices, so that the positioning accuracy is much smaller than the distance between sensor devices (the distance between data collection points). When the distance between sensor devices is 20m or even larger, the positioning accuracy can reach 1m.

[0076] The above method of the present invention can be used for discrete vibration sensor data such as velocity type, acceleration type and hydrophone type, and can also be used for distributed optical fiber sensor data. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0078] Figure 1 It is a schematic diagram of the composition of a pressure water pipeline leakage detection / monitoring system according to a preferred embodiment of the present invention;

[0079] Figure 2 It is a principle diagram of a monitoring method of a pressure water pipeline leakage detection / monitoring tracing method according to a preferred embodiment of the present invention;

[0080] Figure 3 It is a measured waveform diagram of leakage noise of a pressure water pipeline leakage detection / monitoring tracing method according to a preferred embodiment of the present invention;

[0081] Figure 4It is a schematic diagram of leakage point location of a pressure water pipeline leakage detection / monitoring tracing method according to a preferred embodiment of the present invention;

[0082] Figure 5 Schematic diagram of the composition of the road under-pressure water pipeline leakage detection system of Application Example 1 of the present invention;

[0083] Figure 6 It is a schematic diagram of components of a long-distance buried pressure water pipeline leakage monitoring system of Application Example 2 of the present invention.

[0084] The marks in the figure are respectively represented as: vibration sensor 1, vibration sensor array 2, data acquisition module 3, data transmission module 4, central server 5, data publishing module 6, public communication network 7, cable 8, mobile base 9, sound insulation cover 10, traction belt 11, traction device 12, distributed acoustic sensor optical fiber 13, distributed acoustic sensor optical fiber demodulator 14, data point position 15, demodulated waveform data 16, water pipeline 101, leakage point 201, leakage point coordinates 202, received leakage noise 203, vibration sensor coordinates 204, leakage noise source 205, ground 301. DETAILED DESCRIPTION

[0085] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0086] Reference Figure 1 As shown, a pressure water pipeline leakage detection / monitoring system according to a preferred embodiment of the present invention includes a sensor device, a data acquisition module 3, a data transmission module 4, a central server 5 and a data publishing module 6.

[0087] The sensing device is arranged along the extension direction of the water pipeline 101 , and is used to sense the leakage noise of the water pipeline 101 ; the sensing device may be a vibration sensor array 2 composed of a plurality of vibration sensors 1 .

[0088] The data acquisition module 3 is used to receive the leakage noise sensed by the sensor device and convert it into a leakage noise digital signal. The input end of the data acquisition module 3 and the vibration sensor array 2 can be connected via a cable 8. The output end of the data acquisition module 3 and the data transmission module 4 can be connected via a cable 8.

[0089] The data transmission module 4 is used to transmit the leakage noise signal digitized by the data acquisition module 3 to the central server 5 according to instructions, and receive control instructions output by the central server 5. The data transmission module 4 and the central server 5 can be connected through a public communication network 7.

[0090] The central server 5 analyzes the received leakage noise digital signal, and determines whether the water pipeline 101 has leaked through calculation and analysis. When the water pipeline 101 has leaked, the leakage point location and leakage amount are further analyzed and calculated to realize leakage detection or monitoring of the pressure water pipeline 101; at the same time, the central server 5 sends a control instruction to the data acquisition module 3.

[0091] The data publishing module 6 is used to publish the analysis results of the central server 5 through a display and / or a terminal device. The terminal device can publish to relevant personnel through a mobile phone APP, a computer, a laptop, a tablet computer, etc.

[0092] In other preferred embodiments, refer to Figure 5 As shown, the sensing device includes a plurality of movable bases 9, a plurality of vibration sensors, a plurality of sound insulation covers 10, a traction belt 11 and a traction device 12.

[0093] A plurality of mobile bases 9 are disposed on the ground 301 and arranged along the extension direction of the water pipe 101 . Each mobile base 9 is provided with a vibration sensor, so that each sensor is tightly coupled with the ground 301 through the mobile base 9 .

[0094] The soundproof cover 10 is arranged outside the mobile base 9, and the vibration sensor is located inside the soundproof cover 10, that is, the soundproof cover 10 is buckled on the outside of the vibration sensor and the mobile base 9; the soundproof cover 10 is used to block external environmental noise and couple to the vibration sensor through air.

[0095] The traction belt 11 sequentially connects a plurality of movable bases 9 into one body to form a linear sensor array (ie, a vibration sensor array).

[0096] The traction device 12 is connected to one end of the traction belt 11, and can drive the traction belt 11 to move along the ground 3 under traction, thereby driving the plurality of mobile bases 9 and the vibration sensor to move as a whole. The traction device 12 can be a traction trolley.

[0097] As a preferred embodiment, the linear array of sensors is connected to the data acquisition module via a cable; the data acquisition module is connected to the central processing unit via a cable. The data acquisition module and the central processing unit are installed on the traction vehicle.

[0098] In other preferred embodiments, refer to Figure 6As shown, the sensing device is a distributed acoustic sensor optical fiber 13, and the data acquisition module is a distributed acoustic sensor optical fiber demodulator 14. 15 shown in the figure is the data point position, and 16 is the demodulated waveform data.

[0099] The distributed acoustic sensor optical fiber 13 is arranged inside the water pipeline 101 along the pipeline axis, and one end of the distributed acoustic sensor optical fiber 13 extends to the outside of the water pipeline 101. The distributed acoustic sensor optical fiber 13 is used to transmit optical signals and sense vibrations at the same time.

[0100] The distributed acoustic sensor optical fiber demodulator 14 is connected to one end of the distributed acoustic sensor optical fiber 13 and is used to send an optical signal to the distributed acoustic sensor optical fiber 13 and obtain acoustic information of each point along the distributed acoustic sensor optical fiber 13 by measuring and analyzing the return optical signal.

[0101] In another embodiment, a method for tracing the source of leakage detection / monitoring of a pressure water pipeline is provided, comprising:

[0102] S1: A sensor device is arranged along the extension direction of the water pipeline to sense the leakage noise of the water pipeline, and the central server is used to analyze the received leakage noise digital signal, and it is determined through calculation and analysis whether the water pipeline is leaking, and the location of the leakage noise source is located according to the analysis results, so as to determine the location of the leakage point, specifically:

[0103] Reference Figure 2 As shown, it is assumed that the N vibration sensors 1 arranged along the pipeline are p i , i = 1, 2, 3, ... N, the coordinates of the N vibration sensors 204 are x i , i=1,2,3,...N, the received signals are s i (t), i=1, 2, 3, ... N, the leakage point (leakage noise source 205) is located at x=x0.

[0104] Assume that the noise signal emitted by the leakage noise source 205 is w(t), its spectrum is W(f), and the signals received by any two sensors m and n are s m (t) and s n (t), whose spectra are S m (f) and S n (f), and let v represent the propagation speed of noise along the medium, f represent the frequency, π represent the circumference, j represent the imaginary unit, Exp() represent the exponential function, then:

[0105] s m (t) = w(t-(x m -x0) / v) ①

[0106] and

[0107] s n (t) = w(t-(x n -x0) / v)①'

[0108] Their Fourier spectra are:

[0109] S m (f) = W(f) * Exp(-j2πf((x m -x0) / v)) ②

[0110] and

[0111] S n (f)=W(f) * Exp(-j2πf((x n -x0) / v))②'

[0112] Then the signal s m (t) and s n The cross spectrum of (t) is:

[0113]

[0114] Here

[0115]

[0116] The difference in propagation distance (x n -x m ) caused by the signal phase lag, which is caused by the distance difference (x n -x m ) and propagation speed (v) are uniquely determined. According to equations ③ and ④, if the first sensor p1 is taken as the reference point, the values ​​of each sensor (p i , i=1,2,3,...N)signal (s i The cross spectrum of the signal of sensor p1 (s1(t)), i = 1, 2, 3, ... N), can be obtained:

[0117]

[0118] In the above formula, |W(f)| 2 ≥0, (x1-x i ) is a known quantity, so the propagation speed (v) of the leakage noise can be obtained by the following idea:

[0119] Assume a velocity v k , calculated at speed v kThe phase difference between the i-th sensor and the first sensor:

[0120]

[0121] Then from the cross spectrum S 1,i The phase angle of (f) is eliminated This operation is equivalent to propagating the position of sensor p1 to p i The leakage noise signal at the position of p i Trace back to p1;

[0122] Then, the traced signals are superimposed and the standardized superposition energy of the signals is calculated:

[0123]

[0124] The above formula means that the N traced cross spectra are summed up first, and then the absolute value is calculated and divided by the number of cross spectra involved in the superposition. k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the speed v used for tracing k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k Therefore, the propagation speed of leakage noise can be obtained by using the following speed scanning method.

[0125] The velocity scanning method involves determining a possible minimum propagation velocity V min and the maximum propagation speed V max , and then increase the speed by a certain increment of δv, so that the propagation speed is V min Increase to V max , calculate the standardized superposition energy E corresponding to different propagation speeds according to formula ⑦ k (f), find the maximum superposition energy E 0 (f) The corresponding propagation speed V o It is the actual propagation speed of leakage noise.

[0126] When the propagation speed V is obtained o Then, according to the above formula ②, for all N sensors (p i , i = 1, 2, 3, ... N) data, assuming that the position of the leakage noise source 205 is x k , the calculated signal is x k Propagate to sensor p i Phase difference caused by position:

[0127]

[0128] Then from the sensor p i The spectrum S i The phase angle of (f) is eliminated This operation is equivalent to placing the sensor p i The leakage noise signal at the position is from p i Trace back to x k , and then calculate the normalized superposition energy of the signal:

[0129]

[0130] The above formula means that the N traced spectra are summed first, and then the absolute value is calculated and divided by the number of spectra involved in the superposition. k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the assumed leakage point 201 position x k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k Therefore, the location of the leakage noise source 205 (ie, the leakage point 201) can be determined by using the following field source scanning method.

[0131] The field source scanning method includes: determining a possible minimum leakage noise source 205 position X min and the maximum leakage noise source position X max Then, with a position increment δx, the position of the leakage noise 205 is changed from X min Change to X max , use formula ⑨ to calculate the different assumed leakage noise 205 positions x k The corresponding normalized superposition energy E k (f), find the maximum superposition energy E 0 (f) Corresponding leakage noise 205 position x 0 It is the actual position (x0) of the leakage point 201, that is, the leakage point coordinate 202.

[0132] S2: Use the central server to calculate the noise source intensity at the leakage point, and determine the leakage degree according to the noise source intensity, specifically,

[0133] The amplitude of the leakage noise reflects the severity of the leakage and decays with the propagation distance. Let T be the length of the received signal, sensor p i , i=1,2,3,...N received leakage noise s i The average amplitude of (t) A i , i=1,2,3,...N can be expressed as:

[0134]

[0135] The signal amplitude A of N sensors in formula ⑩ i , i = 1, 2, 3, ... N and the position x of N sensors i , i=1,2,3,...N, we can establish the relationship A=g(x) between the leakage noise intensity A and the position x, and then substitute the position coordinate x0 of the leakage point 201 (the coordinate of the leakage point 202), we can get the amplitude of the leakage noise at the leakage point 201 A0=g(x0), and then through the calibration experiment, we can get the relationship between the leakage noise amplitude and the leakage degree (liters / minute) I=Q(A), and thus get the severity of the leakage as I0=Q(A0).

[0136] S3: The steady-state random process method is used to analyze the leakage noise data to improve the inference accuracy of the leakage point 201 position and the stability of the result. That is, the inference accuracy of the leakage point 201 and the anti-interference measures are improved.

[0137] Depend on Figure 3 It can be seen that the waveform diagram of the leakage noise is actually measured. It can be seen that the amplitude and spectrum of the leakage noise waveform are statistically stable, which conforms to the steady-state random process. The steady-state random process theory can be used to analyze the leakage noise data to improve the accuracy of the leakage point location inference and the stability of the results. The specific steps are as follows:

[0138] S31: Divide the monitoring data into M segments of equal length to obtain a set of monitoring data [s i m ], the subscript i = 1, 2, 3, ... N represents the sensor number, and the superscript m = 1, 2, 3, ... M represents the data segment number.

[0139] S32: Taking the first sensor p1 as the reference point, first use the first segment of data to obtain the remaining sensors (p i , i=1,2,3,...N)signal (s i 1 (t), i = 1, 2, 3, ... N) and the signal of sensor p1 (s1 1 The cross spectrum (S 1 i,1 (f));

[0140] S33: Calculate the remaining sensors (p i , i=1,2,3,...N)signal (s i 2 (t), i = 1, 2, 3, ... N) and the signal of sensor p1 (s1 2 The cross spectrum (S 2i,1 (f));

[0141] S34: Repeat the above process according to step S33 to obtain the cross spectrum (S m i,1 (f), m = 1, 2, 3, ... M);

[0142] S35: Obtain the ensemble average of the cross-spectrum:

[0143] S av i,1 (f)=(Σ(S m i,1 (f), m=1,2,3,...M)) / M

[0144] S36: The cross-spectrum ensemble average S av i,1 (f) Replace the cross spectrum S in equation ⑦ i,1 (f) The propagation velocity of the leakage noise can be obtained by using the velocity scanning method.

[0145] S37: For each segment of data, calculate the superposition energy E according to formula 9 k,m (f), superscript k = 1, 2, 3, ... represents the field source scanning sequence number, and superscript m = 1, 2, 3, ... M represents the data segment sequence number.

[0146] S38: Find the ensemble average of the superposition energy:

[0147] E k,av (f)=(Σ(E k,m (f), m=1,2,3,...M)) / M

[0148] S39: Find out the field source position corresponding to the maximum superposition energy, which is the position of the leakage point 201, such as Figure 4 shown.

[0149] Application Example 1

[0150] Reference Figure 5 As shown, the pressure water pipeline leakage detection / monitoring system described in the above embodiment is applied to the leakage detection of water pipelines under roads.

[0151] The leakage detection / monitoring system of the pressure water pipeline 101 includes a sensor device, a data acquisition module 3 and a central server 5. Since it is used for on-site detection, the various parts of the system are directly connected with a cable 8, and the detection results are directly displayed on the screen of the central server 5, so the data transmission module 4 and the data publishing module 6 are not required.

[0152] The sensing device includes a leakage noise detector unit, a traction belt 11 and a traction vehicle, wherein the leakage noise detector unit is composed of a vibration sensor 1, a soundproof cover 10 and a movable base 9.

[0153] The vibration sensor 1 is mounted on a movable base 9 . During detection, the sensor is tightly coupled to the ground through the base. During movement, the sensor, the movable base 9 and the soundproof cover 10 are pulled along the ground by the traction of the traction belt 11 .

[0154] The soundproof cover 10 is buckled on the outside of the sensor and the mobile base 9 to prevent external environmental noise from being coupled to the sensor through the air.

[0155] The leakage noise detector units are connected by a traction belt 11 to form a sensor linear array, and the spacing between the leakage noise detector units is 5.0m.

[0156] The linear array of sensors is connected to the data acquisition unit via cable 8.

[0157] The data acquisition module 3 is directly connected to the central server 5 via a cable 8 .

[0158] The data acquisition module 3 is directly connected to the tractor via a traction belt 11 .

[0159] The data acquisition module 3 and the central server 5 are installed on the tractor.

[0160] The above-mentioned application example 1 uses the pressure water pipeline leakage detection / monitoring system as a detection instrument for the application of leakage detection of water pipeline 101 under the road. The trunk pipelines of the urban tap water network are generally laid under the road. Due to the influence of road vibration and load, leakage is easy to occur. Once leakage occurs, if it is not discovered in time, it is very easy to cause major accidents such as road collapse. In addition, due to the busy traffic on urban roads and high environmental noise, the traditional leakage detection method has poor effect. This application example uses a traction-type sensor device, which can not only make full use of the flat road surface, facilitate traction and movement, and improve detection accuracy, but also because the noise source of vehicle driving and other noise is not fixed and random, the above-mentioned system is based on the processing method of steady-state random process to overcome the influence of such noise.

[0161] Application Example 2

[0162] Reference Figure 6 As shown, the pressure water pipeline leakage detection / monitoring system described in the above embodiment is applied to long-distance large-scale pressure water pipeline monitoring.

[0163] The leakage detection / monitoring system of the pressure water pipeline 101 includes: a distributed acoustic sensing optical fiber, a data acquisition module 3, a central server 5 and a data publishing module 6. Since the optical fiber can be directly extended to the monitoring room, a data transmission module is not required.

[0164] The distributed acoustic sensing optical fiber is arranged inside the pressure water pipeline 101 along the pipeline axis, and one end of the optical fiber is located outside the pipeline and extends to the monitoring room, that is, above the ground 301. The optical fiber is both an optical signal transmission channel and a sensitive element for sensing vibration.

[0165] The data acquisition module 3 uses a distributed acoustic sensing fiber demodulator. The distributed acoustic sensing fiber demodulator is placed in the monitoring room and connected to the distributed acoustic sensing fiber. Its function is to send optical signals to the distributed acoustic sensing fiber and obtain acoustic (vibration) information at each point along the fiber by measuring and analyzing the returned optical signals.

[0166] The central server 5 receives and analyzes the leakage noise monitoring data sent by the demodulator, analyzes whether leakage has occurred, and if leakage has occurred, analyzes the location of the leakage point and the amount of leakage, and transmits the analysis results to the data publishing module 6.

[0167] The function of the data publishing module 6 is to publish the detection / monitoring results to relevant personnel through means such as a display and / or a mobile phone APP.

[0168] The above application example is the application of the pressure water pipeline leakage detection / monitoring system as a monitoring instrument for leakage detection of long-distance large-scale water pipeline 101. In view of the long-distance, large-scale buried water pipeline’s long distance, large diameter, and complex surface conditions, distributed acoustic optical fiber is selected as the sensor and data transmission channel of leakage noise. The distributed acoustic optical fiber is arranged inside the water pipe along the axial direction of the water pipe, and the other end is led out of the pipe and connected to the distributed acoustic sensing optical fiber demodulator. Due to the current technical level and cost limitations, the current positioning accuracy of long-distance optical fiber monitoring is generally 20m, which is far from the actual demand. However, this system is based on the traceability tracking method, which can increase the positioning accuracy of the leakage point to 1m, which can meet the engineering needs.

[0169] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which will not affect the essence of the present invention.

Claims

1. A pressure water pipeline leakage detection / monitoring method, characterized in that: The method adopts a source tracing method, including: S1: a sensor device is arranged along the extension direction of the water pipeline to sense the leakage noise of the water pipeline, and a central server is used to analyze the received leakage noise digital signal, and it is determined through calculation and analysis whether the water pipeline is leaking, and the position of the leakage noise source is located according to the analysis result, so as to determine the leakage point; S2: Calculate the noise source intensity at the leakage point using the central server, and determine the leakage degree according to the noise source intensity; S3: Use the steady-state random process method to analyze leakage noise data to improve the accuracy of leakage point location inference and the stability of the results; The S1 includes: Assume that N vibration sensors are arranged along the extension direction of the water pipeline and are i , i = 1, 2, 3, ... N, the coordinates of the N vibration sensors are x i , i = 1, 2, 3, ... N, the signals received by the N vibration sensors are s i (t), i = 1, 2, 3, ... N, the leakage noise source is located at x = x0, that is, the leakage point is located at x = x0; Assume that the noise signal emitted by the leakage noise source is w(t), its spectrum is W(f), and the signals received by any two sensors m and n are s m (t) and s n (t), whose Fourier spectra are S m (f) and S n (f), and let v represent the propagation speed of noise along the medium, f represent the frequency, π represent the circumference of a circle, j represent the imaginary unit, and Exp() represent the exponential function; then: s m (t)=w(t-(x m -x0) / v) ① and s n (t) = w(t - (x n - x0) / v) ①’ Their Fourier spectra are: S m (f)=W(f)*Exp(-j2πf((x m -x0) / v)) ② and S n (f)=W(f)*Exp(-j2πf((x n -x0) / v)) ②' Then the signal s m (t) and s n The cross spectrum of (t) is: Above The difference in propagation distance (x n -x m ) caused by the signal phase lag, which is caused by the distance difference (x n -x m ) and propagation speed v are uniquely determined; According to equations ③ and ④, if the first sensor p1 is taken as the reference point, the values ​​of each sensor p i , i=1,2,3,...N signals s i The cross spectrum of the signal s1(t) of sensor p1 and sensor p1 is: In the above formula, |W(f)| 2 ≥0, (x1-x i ) is a known quantity, and the propagation speed v of the leakage noise is obtained by the following method: Assume a velocity v k , calculated at speed v k The phase difference between the next i-th sensor and the first sensor is: Then from the cross spectrum S 1,i The phase angle of (f) is eliminated This is equivalent to propagating the position of sensor p1 to p i The leakage noise signal at the position of p i Trace back to p1; Superimpose the traced signals and calculate the standardized superposition energy of the signals: If the speed v used for tracing k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the speed v used for tracing k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k will become relatively smaller; The propagation velocity of the leakage noise is obtained using the following velocity scanning method: Determine the minimum propagation velocity V min and the maximum propagation speed V max , and then increase the speed by a certain increment of δv, so that the propagation speed is V min Increase to V max , calculate the standardized superposition energy E corresponding to different propagation speeds according to formula ⑦ k (f), find the maximum superposition energy E 0 (f) The corresponding propagation speed V o It is the actual propagation speed of leakage noise; When the propagation speed V is obtained o Then, according to the above formula ②, for all N sensors p i , i = 1, 2, 3, ... N data Fourier spectrum, assuming that the location of the leakage noise source is x k , the calculated signal is x k Propagate to sensor p i Phase difference caused by position: Then from the sensor p i The spectrum S i The phase angle of (f) is eliminated This is equivalent to putting the sensor p i The leakage noise signal at the position is from p i Trace back to x k , and then calculate the normalized superposition energy of the signal: If the assumed leakage point position x k It is correct. The signals after tracing have the same phase angle, and the signal after superposition is the strongest, that is, the superposition energy E k Maximum, if the assumed leak point position x k Incorrect. The signal after tracing cannot reach the same phase. The energy E after superposition is k will become relatively smaller; The following field source scanning method is used to determine the location of the leakage noise source, that is, the location of the leakage point: Determine the minimum leakage noise source location X min and the maximum leakage noise source position X max , and then with a certain position increment δx, the leakage noise source position is changed from X min Change to X max , use formula ⑨ to calculate the assumed different leakage noise source positions x k The corresponding normalized superposition energy E k (f), find the maximum superposition energy E 0 (f) The corresponding leakage noise source position x 0 That is the actual position x0 of the leakage point.

2. The pressure water pipeline leakage detection / monitoring method according to claim 1, characterized in that: The S2 includes: Let T be the length of the received signal, sensor p i , i=1,2,3,...N received leakage noise s i The average amplitude of (t) A i , i=1,2,3,...N is expressed as: The signal amplitude A of N sensors in formula ⑩ i , i = 1, 2, 3, ... N and the position x of N sensors i , i=1,2,3,...N, establish the relationship between the leakage noise intensity A and the position x A=g(x), then substitute the coordinates of the leakage point position x0, and obtain the amplitude of the leakage noise at the leakage point A0=g(x0), and then obtain the relationship between the leakage noise amplitude and the leakage degree I=Q(A) through calibration experiments, and the severity of the leakage is obtained as I0=Q(A0).

3. The method for tracing the source of leakage detection / monitoring of a pressure water pipeline according to claim 2, characterized in that: The S3 is executed according to the following steps: S31: Divide the monitoring data obtained by N sensors into M segments of equal length to obtain a set of monitoring data [s i m ], subscript i = 1, 2, 3, ... N represents the sensor number, [s i m ] The superscript m=1,2,3,...M represents the data segment number; S32: Taking the first sensor p1 as the reference point, use the first segment of data to obtain the remaining sensors p i , i=1,2,3,...N signals s i 1 (t), i=1,2,3,...N and the signal s1 of sensor p1 1 The cross spectrum (S 1 i,1 (f)); S33: Using the data in the second section, calculate the p of each of the remaining sensors i , i=1,2,3,...N signals s i 2 (t), i=1,2,3,...N and the signal s1 of sensor p1 2 The cross spectrum (S 2 i,1 (f)); S34: According to the above process of S33, the cross spectrum S of each segment of data is obtained in sequence. m i,1 (f), m = 1, 2, 3, ... M; S35: Calculate the ensemble average of the cross-spectrum: S av i,1 (f)=(Σ(S m i,1 (f),m=1,2,3,...M)) / M; S36: The cross-spectrum ensemble average S av i,1 (f) Replace the cross spectrum S in equation ⑦ i,1 (f), obtaining the propagation velocity of the leakage noise by using the velocity scanning method; S37: For each segment of data, calculate the superposition energy E according to formula 9 k,m (f), superscript k = 1, 2, 3, ... represents the field source scanning sequence number, superscript m = 1, 2, 3, ... M represents the data segment sequence number; S38: Find the ensemble average of the superposition energy: E k,av (f)=(Σ(E k,m (f),m=1,2,3,...M)) / M S39: Find out the field source position corresponding to the maximum superposition energy, which is the position of the leakage point.

4. A pressure water pipeline leakage detection / monitoring system, characterized in that: The pressure water pipeline leakage detection / monitoring method according to any one of claims 1 to 3 comprises: A sensor device arranged along the extension direction of the water pipeline, the sensor device is used to sense the leakage noise of the water pipeline; A data acquisition module, the data acquisition module is used to receive the leakage noise sensed by the sensor device and convert it into a leakage noise digital signal; The central server receives the leakage noise digital signal fed back by the data acquisition module, analyzes the received leakage noise digital signal, determines whether the water pipeline is leaking through calculation and analysis, and locates the leakage noise source according to the analysis result, that is, determines the location of the leakage point, and calculates the leakage amount at the leakage point, so as to detect or monitor the leakage of the pressure water pipeline; at the same time, the central server sends a control instruction to the data acquisition module.

5. The pressure water pipeline leakage detection / monitoring system according to claim 4, characterized in that: Also includes: A data transmission module, the data transmission module is used to transmit the leakage noise signal digitized by the data acquisition module to the central server according to instructions, and receive control instructions output by the central server; A data publishing module, wherein the data publishing module is used to publish the analysis results of the central server through a display and / or a terminal device.

6. The pressure water pipeline leakage detection / monitoring system according to claim 4, characterized in that: The sensing device comprises: A plurality of mobile bases are arranged on the ground and along the extending direction of the water pipeline, each of the mobile bases is provided with a vibration sensor, so that each of the sensors is tightly coupled with the ground through the mobile base; A soundproof cover is arranged outside the mobile base, and the vibration sensor is located in the soundproof cover, and the soundproof cover is used to block external environmental noise; A traction belt, through which a plurality of the mobile bases are sequentially connected to form a linear array of sensors; A traction device is connected to one end of the traction belt and can drive the traction belt to move along the ground under traction, thereby driving a plurality of movable bases and the vibration sensor to move as a whole.

7. The pressure water pipeline leakage detection / monitoring system according to claim 6, characterized in that: The linear array of sensors is connected to the data acquisition module via a cable.

8. The pressure water pipeline leakage detection / monitoring system according to claim 4, characterized in that: The sensing device is a distributed acoustic sensor optical fiber; The distributed acoustic sensor optical fiber is arranged inside the water pipeline along the pipeline axis, and one end of the distributed acoustic sensor optical fiber extends to the outside of the water pipeline. The distributed acoustic sensor optical fiber is used to transmit optical signals and sense vibrations at the same time.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, a pressure water pipeline leakage detection / monitoring method as claimed in any one of claims 1 to 3 is implemented.

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