Research On Pipeline Leak Detection And Location Method Based On Negative Pressure Wave And Ultra Low Frequency Electromagnetic Wave

Pipelines play an important role in the transportation of oil.Therefore,to ensure the safe transportation of oil and gas is an indispensable measure.However,due to natural disasters and human-caused damages,leaks occur in pipelines and cause serious environmental and economic losses.Therefore,it is a great practical significance to study the detection methods of pipeline leaks and leaks.In this paper,a real-time leakage detection and precise positioning method which based on negative pressure wave and ultra-low frequency electromagnetic wave is studied.The negative pressure wave detection can be used to monitor the running status of the pipeline in real time.If a pipeline leak occurs,it will alaram in time and give a rough position of leakage.Then Ultra-low frequency electromagnetic waves are used to achieve precise positioning of pipeline leaks.This method can solve the problem that the original signal ball detection is time consuming and difficult to locate.This article mainly did the following research work:Firstly,we analyze the reasons for the formation of decompression waves inside the pipeline,and establishes a propagation method of the decompression waves.Then we will establish the magnetic field distribution model of ultra-low frequency electromagnetic waves in this paper.According to the distribution characteristics of ultra-low frequency electromagnetic waves in space,we propose the principle of tracking and positioning and conducted simulation analysis.After that,we introduced the common methods of magnetic field measurement and perfomred lateral ratios,and selected electromagnetic induction as a magnetic field detection method.After completing the theoretical analysis,we proposed the pipeline leakage detection and positioning system program,and analyzed the principle and advantages o2 wavelet transform in pressure signal denoising and signal singularity extraction.Then we design the hardware and software of the system based on the negative pressure wave leakage detection system and the ultra-low frequency electromagnetic wave detection system respectively.For the negative pressure wave monitoring system,we designed a hardware system based on STM32F103ZET6 and combined the signal conditioning circuit and data transmission circuit to achieve pressure data sampling.At the same time,the pressure data and time information will be recorded,and the singular points of the signal are extracted by wavelet transform to improve the detection accuracy and reduce the false alarm rate and locating the leak point.Meanwhile,we designed the upper computer software which based on the Qt development framework to implement data storage,leakage analysis,leak location,and leak alarm.For ultra-low frequency electromagnetic wave detection system,we designed a hardware system based on the embedded processor Exynos4412,combined with signal conditioning circuit,to achieve field strength measurement of ultra-low frequency alternating magnetic field.At the same time,we completed the Linux system migration and embedded software development that based on the Exynos4412 to achieve electromagnetic field signal acquisition tasks and accomplished the localization function of the internal detector based on ultra-low frequency electromagnetic.Finally,we built an experimental system and completed system debugging and test under laboratory conditions.Through preliminary tests,we can see that the detection system that based on negative pressure wave and extremely low frequency electromagnetic wave can achieve detection and location of pipeline leakage.