Self-adaptive valid signal type positioning method for determining leakage of fluid pipeline

Abstract

The invention belongs to the technical field of leakage and loss prevention, examination and position determining, and discloses a self-adaptive valid signal type positioning method for determining leakage of a fluid pipeline. The method comprises the steps of selecting a primary function of wavelet decomposition based on a pipeline leakage signal; determining the number of the optimal decomposition layer of the wavelet decomposition; determining the threshold, and performing wavelet denoising on the leakage signal by a soft-threshold method; setting estimation length and shift step length ofa valid signal; determining the valid signal in the leakage signal; determining the time delay value of the leakage signal arriving at the head end and the tail end of the pipeline based on the validsignal in the leakage signal; decreasing the length of the valid signal to obtain two time delay value sets; counting the average value of the three time delay value sets to obtain the final time delay value; determining the difference of the times of the leakage signal arriving at the head end and the tail end of the pipeline; and calculating the position of a leakage source based on the time difference. Compared with an existing positioning method, the method has the advantages that the influence of noise on the leakage signal is reduced; and the leakage positioning error is reduced.

Description

technical field [0001] The invention belongs to the technical field of leakage prevention, inspection and location determination, and in particular relates to an adaptive effective signal determination fluid pipeline leakage location method. Background technique [0002] At present, the existing technologies commonly used in the industry are as follows: When the oil and gas pipeline is damaged and leaks, the medium in the pipeline is ejected from the leakage point, and the leakage can excite different waves. The frequency range distribution of these waves is related to the size of the leak hole, the leakage speed, and the pressure in the pipe, which can range from a few Hz to Hundreds of kilohertz, these fluctuations include infrasound, audible sound, and ultrasonic waves. In the process of propagation, the leakage sound wave propagates along the pipeline to both sides, the leakage sound signal of the high-frequency part attenuates quickly, and the low-frequency attenuation...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is: due to the use of the traditional cross-correlation analysis method, the calculated value of the time difference is greatly affected by noise, so the positioning accuracy cannot be further improved

[0003] In summary, the problems in the prior art are: Using the traditional cross-correlation analysis method, the calculated value of the time difference is greatly affected by noise, resulting in low positioning accuracy

As a result, the calculated time delay is affected, and the calculated time difference accuracy is low, which ultimately leads to low positioning accuracy

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