Device and method for detecting and positioning leakage of gas transmission pipeline based on conventional data and sound wave signals

Abstract

The invention discloses a device and a method for detecting and positioning leakage of a gas transmission pipeline based on conventional data and sound wave signals. The detecting device comprises a sensor group, a field data acquisition processor, a global positioning system (GPS) receiver, a communication network, a central data gathering processor and a monitoring host. The detecting method comprises the following steps of: respectively acquiring sound wave data and traffic, pressure and temperature conventional data of the upstream and the downstream of the pipeline, filtering background noise from the sound wave data by using wavelet transform, respectively identifying a time domain, a frequency domain and time and frequency domain characteristics of the sound wave signals by combining the conventional data to remove external interference and realize leakage signal characteristic extraction, performing leakage positioning by adopting an improved positioning method based on a related analysis method and a GPS synchronous time method, and giving a theoretical installation distance of sound wave sensors according to a propagation model of the sound wave signals. An interface can be established between the conventional data and a field supervisory control and data acquisition (SCADA) system, and only the sound wave sensors are arranged on the upstream and the downstream of the pipeline, so that the invention has the advantages of low investment, high equipment sensitivity and strong adaptability.

Description

Technical field: [0001] The invention relates to a pipeline leakage detection and positioning device and detection method, which belong to the technical field of gas transmission pipeline fault diagnosis and flow safety assurance. Accurately locate the location of the pipeline leak to ensure the safe production and operation of the gas pipeline. Background technique: [0002] According to the research on the current leak detection and location methods of gas pipelines at home and abroad, the leak detection and location methods are mainly concentrated in several aspects based on negative pressure wave method, transient model method, and acoustic leak detection method. The main domestic and foreign patents There are the following items. [0003] US Patent No. 6,389,881 discloses a pipeline leakage detection and location method based on the sonic method. The method captures the sound wave oscillation caused by the leakage, and eliminates external interference through the wave...

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Problems solved by technology

[0008] (1) Both the infrasound and the low-frequency part of the audible sound of the leak signal can be used as the characteristic frequency band of leak detection, and both can be transmitted remotely. However, the above patents only study the infrasound part of the signal, ignoring the low-frequency part of the audible sound , which is not conducive to signal feature extraction and can easily cause false positives

[0009] (2) None of the above patents clearly proposes how to accurately eliminate external interference (such as compressor start and stop, valve switch, pipeline knocking, etc.). Although the US patent proposes a filtering method using pattern matching, it needs to The processor builds a large waveform database for comparison, and each on-site processor needs to be equipped with data information originally recorded in the on-site computer, making the on-site processor complex in structure and high in cost, which is not conducive to on-site development

[0010] (3) Most of the positioning methods use the GPS time synchronization method to calculate the time difference, and basically do not consider the influence of temperature, pressure, etc. on the propagation speed, and the positioning is not accurate enough

[0011] (4) None of the above patents proposed the proper installation distance of the acoustic wave sensor, but simply proposed to install it on the pipeline, downstream or at the first and last station. However, when the distance between stations is large and the conditions along the pipeline are complicated, low frequency The signal will also be greatly attenuated, so it is necessary to give a suitable installation distance

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