Pipeline leakage detection method

Abstract

The invention discloses a pipeline leakage detection method, and relates to the technical field of pipeline detection. Comprising the steps that pressure pulsation signals of a to-be-detected pipeline are collected through two sensors; performing fast Fourier transform on the pressure pulsation signal of the to-be-detected pipeline to obtain an actual frequency domain signal; the frequency domain signal of the to-be-detected pipeline under the non-leakage working condition is compared with the actual frequency domain signal, the amplitude change of the characteristic frequency is obtained, whether the to-be-detected pipeline leaks or not is judged, other tools can be prevented from being used for re-detection, and the pipeline leakage detection efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline detection, and in particular to a pipeline leakage detection method. Background Art

[0002] Pipeline transportation has the characteristics of large transportation volume and low transportation cost. However, due to the long-term burial of pipelines, they will suffer varying degrees of wear, corrosion, aging and other damage, leading to various forms of leakage. If the location of the leak cannot be found in time, it will cause a lot of property losses, pollute the environment, and pose a safety hazard to people's living environment. Therefore, it is particularly important to detect whether the pipeline is leaking, accurately judge the leakage status of the pipeline, and improve the efficiency of identifying the location of pipeline faults, and to perform pipeline leak detection.

[0003] In the prior art, the specific process of using sensor technology to detect pipeline leaks includes: sensors need to be installed at key locations of the pipeline, and the type of sensor depends on the type of pipeline and leak to be detected. The sensor senses information such as pressure, temperature, and flow in the pipeline, and converts this information into electrical signals or other identifiable signals and transmits them to the monitoring system. After receiving the signal transmitted by the sensor, the monitoring system will perform signal filtering, amplification, digitization and other steps, and then determine whether there is a leak in the pipeline based on the preset algorithm and threshold.

[0004] The defects of the above-mentioned prior art are: although the sensor technology can determine whether there is a leak in the pipeline, determining the specific leak location requires the use of other tools to re-detect the pipeline, which wastes time and resources and reduces the efficiency of pipeline detection. Summary of the invention

[0005] Based on this, it is necessary to provide a pipeline leakage detection method to address the above technical issues.

[0006] An embodiment of the present invention provides a pipeline leakage detection method, comprising:

[0007] A sensor is arranged at each of the upstream and downstream ends of the pipeline to be tested, and the pressure pulsation signal of the pipeline to be tested is collected through the two sensors; the pressure pulsation signal of the pipeline to be tested is subjected to fast Fourier transform to obtain the pressure pulsation signal frequency representing the actual working condition of the pipeline to be tested; the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leakage working condition is compared with the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested, and the size of the characteristic frequency and amplitude is determined by the step amplitude interval to determine the leakage state of the pipeline.

[0008] Optionally, the pressure pulsation signal frequency of the actual working condition of the pipeline to be tested specifically includes:

[0009] For the pressure pulsation signal frequency (h1, hmax ) within the amplitude A, each specific frequency h i The amplitude at can be expressed as:

[0010] A(h i )=A i , for h i ∈{h1,h2,h3,...,h max};

[0011] In the formula, A(h i ) represents the frequency h i The amplitude at A i is the frequency corresponding to h i The specific pressure pulsation signal amplitude of the set {h1,h2,h3,...,h max} contains from h1 to h max All specific frequency points within the interval.

[0012] Optionally, the characteristic frequency of the maximum amplitude of the pressure pulsation signal specifically includes:

[0013] The characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leaking pipeline is h m , the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested is h n .

[0014] Optionally, the step amplitude interval specifically includes:

[0015] If h m <h n , then the interval is (2h m -h n , 2h n -h m );

[0016] If h m >h n , then the interval is (2h n -h m , 2h m -h n );

[0017] Among them, the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leaking pipeline is h m , the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested is h n , if the characteristic frequency h m <h n ,A(h m ) <A(h n ), indicating that the pipeline is leaking.

[0018] Compared with the prior art, the pipeline leakage detection method provided by the embodiment of the present invention has the following beneficial effects:

[0019] The present invention arranges two sensors at the upstream and downstream ends of the pipeline to be tested. When a leak occurs, the filtered signal will reach the two sensors in turn; the characteristic frequency and amplitude of the pressure pulsation signal are compared to determine the pipeline leakage state. This process can avoid the use of other tools for re-testing, greatly improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of identification steps of a pipeline leakage detection method provided in one embodiment;

[0021] Figure 2 A pipeline leakage pressure pulsation signal spectrum diagram of a pipeline leakage detection method under 0.8 MPa working condition provided in an embodiment;

[0022] Figure 3 A pipeline leakage pressure pulsation signal spectrum diagram of a pipeline leakage detection method under 1.2 MPa working condition provided in an embodiment; DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] In one embodiment, a pipeline leakage detection method is provided, the method comprising:

[0025] Embodiment 1

[0026] This embodiment discloses an identification algorithm based on pressure pulsation detection of pipeline leakage status. The steps of the algorithm based on pressure pulsation detection of pipeline leakage are as follows: Figure 1 shown.

[0027] S1 performs fast Fourier transform on the collected pressure pulsation signal to obtain the frequency domain diagram:

[0028]

[0029] In the formula, X [ k ] is the transformed frequency domain signal, indicating the k The complex amplitude of the frequency components, x [ n ] is the original time domain signal sequence, nis the sample index in the time domain, N is the total number of samples in the signal, usually an integer power of 2, and k is the frequency index in the frequency domain, ranging from 0 to N−1.

[0030] S2 compares the frequency domain signal of the detected pipe section with the non-leakage condition to determine whether the pipeline is leaking.

[0031] The frequency domain signal of the pipeline under the non-leakage condition has a specific characteristic frequency and amplitude. When the pipeline leaks, the leakage signal will be superimposed on the original signal, causing the amplitude of the characteristic frequency to change; by comparing the frequency domain signal of the pipeline to be tested with the frequency domain signal under the non-leakage condition, it can be determined whether the pipeline is leaking.

[0032] In this embodiment, the pressure pulsation signal is collected by sensors at both ends of the pipeline, and the signal is fast Fourier transformed through the set sampling rate and analysis time to obtain a frequency domain signal. By comparing the frequency domain signals of the same frequency band of the non-leakage condition and the detection pipeline condition, the amplitude change of the characteristic frequency is obtained to determine whether the pipeline is leaking.

[0033] Embodiment 2

[0034] This embodiment discloses an identification algorithm based on pressure pulsation detection pipeline leakage state, a pipeline leakage detection method for judging pipeline leakage pressure pulsation signal spectrum diagram as shown in Figure 2 and Figure 3 shown.

[0035] S1 performs Fourier transform on the collected pressure pulsation signal to obtain a frequency domain diagram. Figure 2 For the pipeline pressure of 0.8MPa, Figure 3 The working condition is pipeline pressure 1.2MPa.

[0036] S2 extracts the characteristic frequency and maximum amplitude of the pressure pulsation signal of the non-leaking condition and the pipeline to be tested. The characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leaking pipeline is h m , the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested is h n . Pipeline pressure is 0.8MPa, h m =97.68Hz, A(h m )=0.107, h n =97.68Hz, A(h n )=0.284. When the pipeline pressure is 1.2MPa, h m =115.65Hz, A(h m )=0.192, h n =128.16Hz, A(h n )=0.289.

[0037] S3 obtains the characteristic frequency of the maximum amplitude of the pipeline pressure pulsation signal and determines the pipeline leakage state through the step amplitude interval. When the pipeline pressure is 0.8Mpa and 1.2Mpa, h m <h n , the intervals are (91.43, 110.18) and (103.14, 140.67) respectively. m ) <A(h n ), indicating that the pipeline is leaking.

[0038] In this embodiment, the collected pressure pulsation signal is Fourier transformed to obtain a frequency domain diagram, and the different frequency components of the signal can be processed to obtain the maximum amplitude and the corresponding characteristic frequency in the frequency domain. The characteristic frequency of the leakage state of the leakage judgment surface may be greater than that of the non-leakage state, and the increase in the characteristic frequency is more likely to indicate that a leak has occurred in the pipeline.

[0039] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A pipeline leakage detection method, characterized in that: include: A sensor is arranged at each of the upstream and downstream ends of the pipeline to be tested, and the pressure pulsation signal of the pipeline to be tested is collected through the two sensors; the pressure pulsation signal of the pipeline to be tested is subjected to fast Fourier transform to obtain the pressure pulsation signal frequency representing the actual working condition of the pipeline to be tested; the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leakage working condition is compared with the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested, and the size of the characteristic frequency and amplitude is determined by the step amplitude interval to determine the leakage state of the pipeline.

2. A pipeline leakage detection method according to claim 1, characterized in that: The pressure pulsation signal frequency specifically includes: For the pressure pulsation signal frequency (h1, h max ) within the amplitude A, each specific frequency h i The amplitude at can be expressed as: A(h i )=A i , for h i ∈{h1,h2,h3,...,h max }; In the formula, A(h i ) represents the frequency h i The amplitude at A i is the frequency corresponding to h i The specific pressure pulsation signal amplitude of the set {h1,h2,h3,...,h max } contains from h1 to h max All specific frequency points within the interval.

3. A pipeline leakage detection method according to claim 1, characterized in that: The characteristic frequency of the maximum amplitude of the pressure pulsation signal specifically includes: The characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leaking pipeline is h m , the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested is h n .

4. A pipeline leakage detection method according to claim 1, characterized in that: The step amplitude range specifically includes: If h m <h n , then the interval is (2h m -h n , 2h n -h m ); If h m >h n , then the interval is (2h n -h m , 2h m -h n ); Among them, the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the non-leaking pipeline is h m , the characteristic frequency of the maximum amplitude of the pressure pulsation signal of the pipeline to be tested is h n , if the characteristic frequency h m <h n ,A(h m )< A(h n ), indicating that the pipeline is leaking.

5. A pipeline leakage detection method, characterized in that: Including the characteristic frequency, maximum amplitude and step amplitude interval of the pressure pulsation signal, the method described in any one of claims 1-4 is implemented when judging the pipeline leakage state.

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