Liquid conveying pipeline leakage and sewage blocking detection method based on frequency domain

Abstract

The invention discloses a liquid conveying pipeline leakage and sewage blocking detection method based on a frequency domain. According to the method, a signal generator is controlled by a data processor and generates a needed simulation signal; a receiving circuit detects potential difference signals on a receiving electrode in real time, and transmits the potential difference signals to a data sampling device; the data sampling device acquires the potential difference signals transmitted by the receiving electrode at regular time; Fourier transform is performed on the acquired potential difference signals to generate positioning curves; when a probe moves near a defective point, an electric field is affected by the defective point, so that the potential differences received by the receiving electrode change; and the defect of a pipeline is detected according to the change of the positioning curves, and the defect can be positioned according to the relative positons of the probe and the defective point in the positioning curves. The method is widely applied, and is particularly applicable to internal inspection for conveying pipelines for liquid such as crude oil, refined oil, industrial dangerous liquid, sewage or electric conduction media containing pollutants in severe working environments.

Description

technical field [0001] The invention relates to the field of detection of fluid conveying pipelines, in particular to a method for detecting leakage and fouling damage of liquid conveying pipelines due to corrosion, fouling, manufacturing defects, mechanical damage, bad weather, natural disasters and other reasons during use. A method for internal detection of defects. Background technique [0002] Pipeline transportation is one of the five transportation methods following railway transportation, road transportation, waterway transportation, and air transportation, and has become the most important transportation method for crude oil, refined oil, gas, steam and industrial hazardous media. Liquid transportation pipeline is the most important transportation mode of crude oil, refined oil and industrial dangerous liquid medium in petrochemical industry. In a fluid transmission system, piping is an essential element for transmitting fluid power. Liquid transportation pipeline...

AI Technical Summary

Problems solved by technology

Although there are many detection methods in liquid transportation pipelines, these detection methods are not universally applicable

For example, the accuracy of the mechanical internal detection is not enough and there is a contact with the pipeline, which is far from meeting the demand; the internal detection of magnetic flux leakage needs to magnetize the pipeline, which actually limits the material of the pipeline to be detected, and also has requirements for the magnetic properties of the transmission medium; eddy current Due to the limitation of its principle, the detection speed is slow and the corresponding hardware system is also relatively complicated; the coupling problem between the transmission medium and the pipeline material exists in the ultrasonic internal detection, which makes it sensitive to the transmission medium; although the electromagnetic ultrasonic internal detection can better solve the problem of ultrasonic internal The detection is sensitive to the medium, but this method is only effective within 1mm from the detection pipeline, which greatly limits its application, and because the system detects pipeline damage by transmitting / receiving ultrasonic waves, the system hardware and software are more complicated ; Optical imaging internal detection is basically unusable in oily turbid liquids, and there are also problems requiring light sources and complex hardware systems

[0004] The above-mentioned traditional in-pipe detection methods generally have problems such as complex hardware, high power consumption, and sensitivity to detection objects, which have severely restricted the development of online, long-distance, and miniaturized internal detection devices (automatic internal detection robots)

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