CN107620868B - pipeline leakage detection method and device - Google Patents

Abstract

the invention provides a pipeline leakage detection method and device, and relates to the field of pipeline leakage monitoring. The pipeline leakage detection method comprises the following steps: acquiring a negative pressure wave signal caused by pipeline leakage; preprocessing the negative pressure wave signal to obtain a dynamic change sequence of the pressure along the pipeline; determining the interval of the leakage point based on the dynamic change sequence of the pressure along the pipeline; and acquiring the position of the leakage point based on the dynamic change sequence of the pressures at the two ends of the interval where the leakage point is located. The method and the device provided by the invention can be used for segmenting the pipeline detection through a plurality of sensors arranged in the pipeline so as to determine the interval where the leakage point is located, and then positioning the leakage point based on the interval where the leakage point is located.

Description

Pipeline leak detection method and device

technical field

The invention relates to the field of pipeline leakage monitoring, in particular to a pipeline leakage detection method and device.

Background technique

As the fifth largest mode of transportation, pipelines are the most effective way of transporting rheological media such as oil, natural gas, slurry, carbon dioxide, and biofuels. However, with the increase of pipe age, pipeline leakage accidents caused by aging corrosion, geological disasters and man-made damage occur frequently. Therefore, real-time monitoring of pipeline leakage and precise location of leakage points are of great significance to ensure public property and personal safety, protect the environment, and reduce national economic losses.

Existing pipeline leakage detection technologies are mainly divided into four categories: leakage medium detection method, pipe wall parameter detection method, acoustic detection method and optical fiber distributed sensing monitoring method. Due to its simple implementation and easy maintenance, the negative pressure wave monitoring method has become a research hotspot and one of the main technical means in the field of pipeline leakage detection in recent years. However, due to the influence of factors such as signal attenuation and environmental noise during the transmission of the leaked negative pressure wave signal, the inflection point of the negative pressure wave signal is not clear, and the acquisition accuracy of the time difference between the sensors at both ends of the pipeline is reduced, which seriously affects the positioning accuracy and accuracy of the negative pressure wave system. Promotion and application in the pipeline transportation industry.

Contents of the invention

The purpose of the present invention is to provide a pipeline leakage detection method and device, which can effectively improve the above problems.

Embodiments of the present invention are achieved like this:

In the first aspect, an embodiment of the present invention provides a pipeline leakage detection method, the method comprising: acquiring a negative pressure wave signal caused by pipeline leakage; preprocessing the negative pressure wave signal to obtain the pressure along the pipeline the dynamic change sequence of the pressure along the pipeline; determine the interval where the leak point is located based on the dynamic change sequence of the pressure along the pipeline; and obtain the location of the leak point based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located.

In the second aspect, the embodiment of the present invention also provides a pipeline leakage detection device, which includes an acquisition module for acquiring negative pressure wave signals caused by pipeline leakage; a preprocessing module for performing processing on the negative pressure wave signals The preprocessing is to obtain the dynamic change sequence of the pressure along the pipeline; the interval module is used to determine the interval where the leakage point is based on the dynamic change sequence of the pressure along the pipeline; the location module is used to determine the interval where the leak point is located based on the two ends of the interval The dynamic change sequence of the pressure is used to obtain the position of the leakage point.

In the third aspect, the embodiment of the present invention also provides a pipeline leakage detection device, which includes a plurality of sensors, the plurality of sensors are arranged on the pipeline to be tested at intervals along the axis of the pipeline to be tested, and the plurality of sensors The distance between them is adjustable, and the sensor is used to detect the negative pressure wave signal generated by the leakage of the pipeline to be tested.

In the pipeline leakage detection method and device provided by the embodiments of the present invention, the negative pressure wave signal caused by the pipeline leakage is first obtained; then the negative pressure wave signal is preprocessed to reduce the interference of noise on the effective negative pressure wave signal, and the obtained The dynamic change sequence of the pressure along the pipeline; then based on the dynamic change sequence of the pressure along the pipeline, determine the interval where the leakage point is located, so as to narrow the calculation range and make the calculation result more accurate; finally, based on the pressure at both ends of the interval where the leakage point is located The dynamic change sequence of the leakage point is obtained to obtain the location of the leakage point, that is, to realize the precise positioning of the leakage point. Compared with the prior art, the method and device provided by the embodiment of the present invention segment the pipeline detection through multiple sensors installed in the pipeline to determine the interval where the leak point is located, and then locate the leak point based on the interval where the leak point is located , can realize the accurate acquisition of the negative pressure wave signal inflection point and time difference, its positioning accuracy is high, and the field operability is strong, and it can be widely used in the leakage monitoring of long-distance oil and gas pipelines and urban water supply and heating pipelines.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

FIG. 1 is a structural block diagram of an electronic device applicable to an embodiment of the present invention;

Fig. 2 is a block flow diagram of the pipeline leakage detection method provided by the first embodiment of the present invention;

FIG. 3 is a flowchart of the sub-steps of step S210 in the first embodiment of the present invention;

FIG. 4 is a flowchart of the sub-steps of step S220 in the first embodiment of the present invention;

FIG. 5 is a flowchart of the sub-steps of step S230 in the first embodiment of the present invention;

Fig. 6 is the signal sequence curve of the negative pressure wave monitored by sensors along the pipeline after leakage provided by the first embodiment of the present invention;

Fig. 7 is the wavelet transformed curve of the sensor monitoring negative pressure wave signal provided by the first embodiment of the present invention;

Fig. 8 is the dynamic pressure curve after wavelet transformation of the pressure sequence on both sides of the leakage point provided by the first embodiment of the present invention and using the difference algorithm;

Fig. 9 is a correlation function curve obtained after applying a cross-correlation algorithm to the dynamic pressure change sequence provided by the first embodiment of the present invention;

Fig. 10 is a schematic diagram of obtaining the time difference between two signals by quadratic curve fitting;

Fig. 11 is a structural block diagram of a pipeline leak detection device provided by the second embodiment of the present invention;

Fig. 12 is a structural block diagram of the preprocessing module provided by the second embodiment of the present invention;

Fig. 13 is a structural block diagram of the interval module provided by the second embodiment of the present invention;

Fig. 14 is a structural block diagram of a location module provided by a second embodiment of the present invention;

Fig. 15 is a schematic structural diagram of a pipeline leak detection device provided by a third embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

FIG. 1 shows a structural block diagram of an electronic device 100 applicable to an embodiment of the present application. As shown in FIG. 1 , the electronic device 100 may include a memory 110 , a storage controller 120 , a processor 130 , a display screen 140 and a pipeline leak detection device. For example, the electronic device 100 may be a personal computer (personal computer, PC), a tablet computer, a smart phone, a personal digital assistant (personal digital assistant, PDA) and the like.

The elements of the memory 110 , the memory controller 120 , the processor 130 , and the display screen 140 are electrically connected directly or indirectly to realize data transmission or interaction. For example, these components can be electrically connected through one or more communication buses or signal buses. The pipeline leakage detection method respectively includes at least one software function module that can be stored in the memory 110 in the form of software or firmware (firmware), for example, the software function module or computer program included in the pipeline leakage detection device.

The memory 110 can store various software programs and modules, such as program instructions/modules corresponding to the pipeline leakage detection method and device provided in the embodiment of the present application. The processor 130 executes various functional applications and data processing by running the software programs and modules stored in the memory 110 , that is, implements the pipeline leakage detection method in the embodiment of the present application. Memory 110 may include but not limited to random access memory (Random Access Memory, RAM), read-only memory (Read Only Memory, ROM), programmable read-only memory (Programmable Read-Only Memory, PROM), erasable read-only memory Memory (Erasable Programmable Read-Only Memory, EPROM), Electrically Erasable Programmable Read-Only Memory (Electric Erasable Programmable Read-Only Memory, EEPROM), etc.

The processor 130 may be an integrated circuit chip with signal processing capability. Above-mentioned processor can be general-purpose processor, comprises central processing unit (Central Processing Unit, be called for short CPU), network processor (NetworkProcessor, be called for short NP) etc.; Can also be digital signal processor (DSP), application-specific integrated circuit (ASIC) , off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

The electronic device 100 applied in the embodiment of the present invention can also have a self-display function in order to realize the pipeline leakage detection method, and the display screen 140 can provide an interactive interface (such as a user operation interface) between the electronic device 100 and the user. ) or for displaying image data for user reference. For example, data such as negative pressure wave signal images collected by pipeline leak detection devices can be displayed.

Before introducing specific embodiments of the present invention, it should first be explained that the present invention is an application of computer technology in the field of pipeline leakage monitoring. During the implementation of the present invention, the application of multiple software function modules will be involved. The applicant believes that after carefully reading the application documents and accurately understanding the realization principle and purpose of the present invention, and in combination with existing known technologies, those skilled in the art can fully implement the present invention by using their software programming skills. All the software functional modules mentioned in the application documents of the present invention belong to this category, and the applicant will not list them one by one.

first embodiment

Please refer to Fig. 2, the present embodiment provides a kind of pipeline leak detection method, described method comprises:

Step S200: acquiring negative pressure wave signals caused by pipeline leakage;

In this embodiment, a plurality of sensors are arranged at intervals in the section to be tested of the pipeline, and each sensor can be used to obtain a pressure signal in the section to be tested. It can be understood that when a leak occurs in the pipeline to be tested, the pressure at the leakage point of the pipeline will drop suddenly due to the pipeline leakage, that is, a negative pressure wave signal will be generated, and the negative pressure wave signal will be obtained through sensor detection, namely Subsequent analysis of the position of the leakage point can be performed according to the negative pressure wave signal.

In this embodiment, the sensors may be electronic sensors or optical fiber sensors or other sensors capable of pipeline pressure detection, and each of the sensors may transmit the collected negative pressure wave signals in a wired or wireless manner.

Step S210: Preprocessing the negative pressure wave signal to obtain a dynamic change sequence of pressure along the pipeline;

In this embodiment, by preprocessing the negative pressure wave signal, the interference of other noises in the pipeline on the effective negative pressure wave signal can be reduced, and finally an effective dynamic change sequence of pressure along the pipeline can be obtained.

Step S220: Based on the dynamic change sequence of the pressure along the pipeline, determine the interval where the leakage point is located;

In this embodiment, by analyzing the relationship between the dynamic change sequence of the pressure along the pipeline and the position in the pipeline, the area where the pressure changes in the pipeline is the most obvious can be found, and the approximate interval where the leak point is located can be determined based on this. For example, by calculating the cross-correlation coefficient of the pressure dynamic change sequence of every two adjacent sensors in the pipeline, the cross-correlation coefficient can be used to characterize the obvious degree of pressure change in the interval, and the two with the largest cross-correlation coefficient The area between adjacent sensors is used as the interval where the leak point is located.

Step S230: Obtain the location of the leak point based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located.

In this embodiment, by analyzing the dynamic change sequence of the pressure at both ends of the interval where the leak point is located, the time difference for the negative pressure wave signal generated by the leak point to reach the sensors at both ends of the interval where the leak point is located can be obtained, and based on the time difference Calculate the specific location of the leak point based on the propagation speed of the negative pressure wave signal, that is, realize the precise positioning of the leak point.

Please refer to FIG. 3, in this embodiment, further, the step S210 may include the following sub-steps:

Step S300: performing wavelet transformation on the negative pressure wave signal to obtain a wavelet-transformed negative pressure wave signal sequence;

In this embodiment, the example is based on the laboratory pipeline leakage monitoring experiment platform, the pipeline material is carbon steel pipeline, the total length of the pipeline is 112 meters, the inner diameter is 100mm, the pressure range is 0-0.4Mpa, and the data sampling frequency is 1kHz. Install pressure sensors A, B, C, D, and E at both ends of the pipeline, respectively, and monitor the negative pressure wave signal sequence by simulating the pipeline leakage sensor through the opening and closing of the valve.

The leakage negative pressure wave signal monitored by each sensor in real time is a set of discrete sequences, as shown in Figure 6.

In this embodiment, by performing wavelet transform processing on the negative pressure wave signal, the interference of noise on the effective negative pressure wave signal can be reduced.

The wavelet-transformed negative pressure wave signal sequence includes the negative pressure wave inflection point and the complete negative pressure wave signal before and after the pressure at the inflection point stabilizes, wherein the negative pressure wave inflection point can be selected using a fixed threshold method. For example, if a fixed threshold k is selected, when X _n-1 -X _n > k, point n is the selected inflection point of the negative pressure wave signal.

Figure 7 shows the signal curve obtained after wavelet transform of the negative pressure wave signal including the inflection point in Figure 6 .

Step S310: Perform difference calculation on the wavelet-transformed negative pressure wave signal sequence to obtain a dynamic change sequence of pressure along the pipeline.

In this embodiment, the differential calculation of the negative pressure wave signal sequence after the wavelet transformation may specifically be as follows: first, the negative pressure wave signal sequences collected by the two sensors at the endpoints on both sides of the pipeline are respectively A(x) , B(x), the pressure sequence after wavelet transformation is P _A (i), P _B (i), where i is any data of data sequence 1, 2...L+1, and L+1 is the data sequence length, then the dynamic pressure change sequences X(i) and Y(i) at both ends of the pipeline obtained after differential calculation of P _A (i) and P _B (i) are:

X(i)=P _A (i+1)-P _A (i)i=1,2,3...L

Y(i)=P _B (i+1)-P _B (i)i=1,2,3...L

After the above difference calculation, the obtained curve is shown in FIG. 8 .

Please refer to FIG. 4, in this embodiment, further, the step S220 may include the following sub-steps:

Step S400: Based on the dynamic change sequence of the pressure along the pipeline, obtain the dynamic pressure change sequence of multiple groups of two adjacent monitoring points in the pipeline;

In this embodiment, the pressure dynamic change sequence of every two adjacent sensors in the pipeline is acquired through the same method as above. It can be understood that the monitoring point is the position corresponding to each sensor, and each monitoring point corresponds to a sensor.

Step S410: Calculate multiple sets of cross-correlation coefficients of the pressure dynamic change series of the two adjacent monitoring points, and select the two adjacent monitoring points corresponding to the maximum cross-correlation coefficient, and calculate the maximum cross-correlation coefficient corresponding to The area between two adjacent monitoring points is taken as the interval where the leakage point is located.

In this embodiment, the calculation of the cross-correlation coefficient may specifically be assuming that the pressure dynamic change sequences monitored by two adjacent sensors in the pipeline are respectively X(i) and Y(i), where i is the data sequence 1, 2...L arbitrary data, L is the length of the data sequence, then the correlation coefficient ρ _xy can be calculated according to the following formula:

in, are the mean values of sequences X(i) and Y(i), respectively.

For the pipeline dynamic pressure change sequence monitored by the sensor array in the experiment, the above formulas are used to calculate the cross-correlation coefficients of two adjacent sensors ρ _AB =0.76, ρ _BC =0.52, ρ _CD =0.65, and ρ _DE =0.44. At this time The sensor interval where the maximum cross-correlation coefficient is located is taken as the interval where the leak point is located, that is, the interval between sensor A and sensor B is used as the interval where the leak point is located.

Please refer to FIG. 5, in this embodiment, further, the step S230 may include the following sub-steps:

Step S500: Obtain the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located;

In this embodiment, the pressure dynamic change sequence of two adjacent sensors corresponding to the maximum cross-correlation coefficient screened out in the previous step is the dynamic change sequence of pressure at both ends of the interval where the leakage point is located.

Step S510: Based on the cross-correlation algorithm, calculate the correlation function extremum of the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located;

In this embodiment, the cross-correlation algorithm may specifically be, assuming that the pressure dynamic change sequences at both ends of the interval where the leakage point is located are respectively X(i), Y(i), where i is the data sequence 1, 2...L Arbitrary data, L is the length of the data sequence, where the lengths of X(i) and Y(i) can be the same or different. When the lengths of the two are different, zeros are added after the short sequence until the length of the two is equal. Calculating the cross-correlation function R _xy of two sequences can be:

Then calculate the extremum of the cross-correlation function R _xy and the abscissa m corresponding to the extremum of the function. The correlation function curve obtained by applying the above cross-correlation algorithm to the dynamic pressure change sequences X(i) and Y(i) in the experiment of this embodiment is shown in FIG. 9 . The ordinate in Figure 9 is the value of the cross-correlation function _Rxy , and the abscissa is the sampling point m. Specifically, two points adjacent to the extreme point on the cross-correlation function can be fitted with the extreme point, Obtain a fitting function, then obtain the sampling point m corresponding to the maximum value of the fitting function, and combine the sampling point m corresponding to the maximum value of the fitting function with the two discrete sequences X(i) and Y(i) By multiplying the sampling frequency time interval δ, the time difference between the arrival of the negative pressure wave signal generated by the leakage point at both ends of the interval where the leakage point is located can be obtained.

To further illustrate the above cross-correlation algorithm, let the sequence X(i) be {1,2,4,2,1}, and the sequence Y(i) be {2,2,1}, calculate the cross-correlation of the two sequences Correlation function R _xy . Since the length of the sequence Y(i) is less than X(i), Y(i) is first complemented and transformed into Y(i) as {2,2,1,0,0}, so L=4, m =0, ±1, ±2, ±3, the calculation results using the calculation formula of the above cross-correlation function R _xy are shown in Table 1.

Table 1

It can be seen from Table 1 that when m=1, the cross-correlation function R _xy takes a maximum value of 14.

Step S520: Select three points adjacent to the extremum of the correlation function to perform parabolic interpolation to obtain a parabolic function, and use the abscissa corresponding to the maximum value of the parabolic function as the negative pressure wave signal generated by the leak point to reach the leak The time difference between the two ends of the interval where the point is located;

In this embodiment, the difference algorithm may specifically be, assuming that the extremum k of the cross-correlation function obtained by the above-mentioned cross-correlation algorithm=14, then two points (0, 10) adjacent to the extremum k are taken, (2,13) and (1,14) perform quadratic curve fitting to obtain the fitting function:

f(m)＝-2.5m ² +6.5m+10

Calculate the maximum value of the function f(m) and the abscissa corresponding to the maximum value τ=1.30, set the sampling frequency time interval of two discrete sequences X(i) and Y(i) as δ, then the two signals X(i ) and Y(i) have a time shift of Δt=δτ, as shown in FIG. 10 .

Step S530: Obtain the location of the leak point based on the time difference between the arrival of the negative pressure wave signal generated by the leak point at both ends of the interval where the leak point is located.

In this embodiment, the leakage point can be precisely located by using a negative pressure wave positioning algorithm. The negative pressure wave positioning algorithm can specifically be, assuming that the distance L between the two sensors at the two ends of the interval where the leak point is located, and the negative pressure wave propagation speed as V, the relevant algorithm in this embodiment is used to calculate the negative pressure wave signal monitored by the two sensors The time difference is Δt, then the distance between the leak point and one of the sensors is:

At this time, the accurate acquisition of the location of the pipeline leakage point is realized.

The method provided in this embodiment realizes the accurate acquisition of the inflection point and time difference of the negative pressure wave signal by using wavelet transform, negative pressure wave signal difference calculation, correlation function analysis and secondary fitting processing, and improves the positioning accuracy of the system. With high positioning accuracy and strong on-site operability, it can be widely used in leakage monitoring of long-distance oil and gas pipelines and urban water supply and heating pipelines.

second embodiment

Please refer to FIG. 11 , this embodiment provides a pipeline leak detection device 600, which includes:

An acquisition module 610, configured to acquire negative pressure wave signals caused by pipeline leakage;

A preprocessing module 620, configured to preprocess the negative pressure wave signal to obtain a dynamic change sequence of pressure along the pipeline;

An interval module 630, configured to determine the interval where the leakage point is located based on the dynamic change sequence of the pressure along the pipeline;

The position module 640 is configured to obtain the position of the leak point based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located.

Please refer to FIG. 12. In this embodiment, further, the preprocessing module 620 may also include the following units:

A wavelet transformation unit 621, configured to perform wavelet transformation on the negative pressure wave signal to obtain a wavelet-transformed negative pressure wave signal sequence;

The difference unit 622 is configured to perform a difference operation on the wavelet-transformed negative pressure wave signal sequence to obtain a dynamic change sequence of the pressure along the pipeline.

Please refer to FIG. 13 , in this embodiment, further, the interval module 630 may also include the following units:

The partitioning unit 631 is configured to obtain, based on the dynamic change sequence of the pressure along the pipeline, the pressure dynamic change sequence of multiple groups of two adjacent monitoring points in the pipeline;

The screening unit 632 is used to calculate the cross-correlation coefficients of the pressure dynamic change series of multiple groups of the two adjacent monitoring points, and to filter out the two adjacent monitoring points corresponding to the maximum cross-correlation coefficient, and to set the maximum cross-correlation The area between two adjacent monitoring points corresponding to the number is taken as the interval where the leakage point is located.

Please refer to FIG. 14. In this embodiment, further, the location module 640 may further include the following units:

An acquisition unit 641, configured to acquire the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located;

A cross-correlation unit 642, configured to calculate the extreme value of the correlation function of the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located based on a cross-correlation algorithm;

The interpolation unit 643 is configured to select three adjacent points on the extremum of the correlation function to perform parabolic interpolation to obtain a parabolic function, and use the product of the abscissa corresponding to the maximum value of the parabolic function and the sampling interval of the data sequence as the leakage point The time difference between the two ends of the interval where the generated negative pressure wave signal arrives at the leakage point;

The positioning unit 644 is configured to obtain the location of the leak point based on the time difference between the arrival of the negative pressure wave signal generated by the leak point at both ends of the interval where the leak point is located.

third embodiment

Referring to FIG. 15 , the present embodiment provides a pipeline leakage detection device 1000 , which includes a plurality of sensors 800 arranged on the pipeline 900 to be tested at intervals along the axis of the pipeline to be tested 900 .

In this embodiment, the distance between the plurality of sensors 800 is adjustable, and the sensors 800 are used to detect the negative pressure wave signal generated by the leakage of the pipeline 900 to be tested. Preferably, the distances between the plurality of sensors 800 are the same. It can be understood that the distances between the multiple sensors 800 may not be completely the same.

In this embodiment, the sensors 800 can be electronic sensors or optical fiber sensors or other sensors capable of pipeline pressure detection, and each of the sensors 800 can transmit the collected negative pressure wave signals to data in a wired or wireless manner. transmission.

To sum up, the pipeline leakage detection method and device provided by the embodiments of the present invention first obtain the negative pressure wave signal caused by the pipeline leakage; then preprocess the negative pressure wave signal to reduce the impact of noise on the effective negative pressure wave Signal interference, to obtain the dynamic change sequence of the pressure along the pipeline; then based on the dynamic change sequence of the pressure along the pipeline, determine the interval where the leak point is located, so as to narrow the calculation range and make the calculation result more accurate; finally, based on the leak point The dynamic change sequence of the pressure at both ends of the interval is used to obtain the position of the leakage point, that is, to realize the precise positioning of the leakage point. Compared with the prior art, the method and device provided by the embodiment of the present invention segment the pipeline detection through multiple sensors installed in the pipeline to determine the interval where the leak point is located, and then locate the leak point based on the interval where the leak point is located , can realize the accurate acquisition of the negative pressure wave signal inflection point and time difference, its positioning accuracy is high, and the field operability is strong, and it can be widely used in the leakage monitoring of long-distance oil and gas pipelines and urban water supply and heating pipelines. The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (4)

1. A pipeline leak detection method, characterized in that the method comprises: Obtain the negative pressure wave signal caused by pipeline leakage; Preprocessing the negative pressure wave signal to obtain a dynamic change sequence of pressure along the pipeline; Determine the interval where the leakage point is located based on the dynamic change sequence of the pressure along the pipeline; Obtaining the position of the leak point based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located; Wherein, the negative pressure wave signal is preprocessed to obtain a dynamic change sequence of the pressure along the pipeline, including: Carrying out wavelet transform to described negative pressure wave signal, obtains the negative pressure wave signal sequence after wavelet transform; Performing a difference operation on the negative pressure wave signal sequence after the wavelet transformation to obtain a dynamic change sequence of the pressure along the pipeline; Wherein, based on the dynamic change sequence of the pressure along the pipeline, the interval of the leakage point is determined, including: Based on the dynamic change sequence of the pressure along the pipeline, the pressure dynamic change sequence of multiple groups of adjacent two monitoring points in the pipeline is obtained; Calculate the cross-correlation coefficients of the pressure dynamic change series of multiple groups of the two adjacent monitoring points, and select the two adjacent monitoring points corresponding to the maximum cross-correlation coefficient, and divide the two adjacent points corresponding to the maximum cross-correlation coefficient The area between the two monitoring points is taken as the interval where the leakage point is located; Wherein, based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located, the position of the leak point is obtained, including: Obtain the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located; Based on the cross-correlation algorithm, calculate the correlation function extremum of the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located; Select three adjacent points on the extreme value of the correlation function to perform parabolic interpolation to obtain a parabolic function, and use the abscissa corresponding to the maximum value of the parabolic function as the negative pressure wave signal generated by the leak point to reach the interval where the leak point is located the time difference between the two ends; The position of the leak point is obtained based on the time difference between the arrival of the negative pressure wave signal generated by the leak point at both ends of the interval where the leak point is located. 2. The method according to claim 1, wherein the negative pressure wave signal sequence after the wavelet transformation comprises negative pressure wave inflection points and complete negative pressure wave signals before and after inflection point pressure stabilization, wherein the negative pressure wave The selection of the inflection point adopts the fixed threshold method. 3. A pipeline leak detection device, characterized in that the device comprises: The acquisition module is used to acquire negative pressure wave signals caused by pipeline leakage; A preprocessing module, configured to preprocess the negative pressure wave signal to obtain a dynamic change sequence of pressure along the pipeline; An interval module, configured to determine the interval where the leakage point is located based on the dynamic change sequence of the pressure along the pipeline; A position module, configured to obtain the position of the leak point based on the dynamic change sequence of the pressure at both ends of the interval where the leak point is located; Wherein, the preprocessing module includes: A wavelet transform unit, configured to perform wavelet transform on the negative pressure wave signal, to obtain a wavelet transformed negative pressure wave signal sequence; A difference unit, configured to perform a difference operation on the wavelet-transformed negative pressure wave signal sequence to obtain a dynamic change sequence of pressure along the pipeline; Wherein, the interval module includes: A partitioning unit, configured to obtain, based on the dynamic change sequence of pressure along the pipeline, the pressure dynamic change sequence of multiple groups of adjacent two monitoring points in the pipeline; The screening unit is used to calculate the cross-correlation coefficients of the pressure dynamic change series of multiple groups of the two adjacent monitoring points, and to filter out the two adjacent monitoring points corresponding to the maximum cross-correlation coefficient, and to use the maximum cross-correlation coefficient The area between the corresponding two adjacent monitoring points is taken as the interval where the leakage point is located; Wherein, the location module includes: An acquisition unit, configured to acquire the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located; The cross-correlation unit is used to calculate the extreme value of the correlation function of the dynamic change sequence of the pressure at both ends of the interval where the leakage point is located based on the cross-correlation algorithm; The interpolation unit is used to select three adjacent points on the extremum of the correlation function to perform parabolic interpolation to obtain a parabolic function, and use the abscissa corresponding to the maximum value of the parabolic function as the negative pressure wave signal generated by the leakage point to reach the The time difference between the two ends of the interval where the leakage point is located; The positioning unit is configured to obtain the location of the leak point based on the time difference between the arrival of the negative pressure wave signal generated by the leak point at both ends of the interval where the leak point is located. 4. A pipeline leak detection device, characterized in that it includes a plurality of sensors, a processor and a memory, the plurality of sensors are arranged on the pipeline to be tested at intervals along the axis of the pipeline to be tested, and one of the plurality of sensors The distance between them is adjustable, and the sensor is used to detect the negative pressure wave signal generated by the leakage of the pipeline to be tested; The memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the steps in the method of any one of claims 1-2 are executed.