Research On Negative Pressure Wave Leak Detection System Of Oil Pipeline

With the rapid economic and social development,the domestic demand for oil and gas resources has increased year by year.Pipeline transportation is convenient and fast,and its cost is low.It is an ideal way for oil and gas transportation.However,with the gradual increase in the proportion of pipeline transportation,domestic pipeline leakage accidents occur frequently,which not only causes major economic losses and casualties,but also seriously pollutes the environment and runs counter to the desire to build beautiful China.In order to be able to detect leaks on the pipeline in a timely manner and further reduce the risk of leakage accidents,it is necessary to effectively monitor the pipeline in real time.This paper studies the negative pressure wave leakage detection technology,and designs and develops a real-time detection and positioning system for oil pipeline leakage.Firstly,according to the propagation law of negative pressure waves,a mathematical model for the generation,propagation and propagation attenuation of negative pressure waves is established.Based on this model,combined with the negative pressure wave leakage detection and positioning principle,a negative pressure wave velocity correction model is established,and improved positioning formulas.Among them,the time synchronization problem of the first and last station computer systems is achieved by using GPS to unify the clocks of the IPC systems at the upstream and downstream sites,and the accuracy can fully meet the requirements;considering the changes of the negative pressure wave velocity with temperature,the linear correction model of negative pressure wave velocity;under complex conditions,if only the negative pressure wave method is used to monitor the oil pipeline system in real time,it is prone to false alarms.Therefore,a combined flow rate judgment mechanism is used to realize leak detection and further improve the Leak detection accuracy and reliability.Secondly,in the system design,the data processing part plays a decisive role for the entire system and directly affects the accuracy and positioning accuracy of the leakage event.Based on the special advantages of wavelet analysis,the system uses wavelet threshold denoising to complete the signal analysis and processing.By comparing the commonly used Symlets wavelet and Daubechies wavelet,the best wavelet base,threshold and wavelet transform orders are selected.The wavelet transform method is used to process the noise signal contained in the original leakage negative pressure wave signal.At the same time,the signal is analyzed in the time domain and frequency domain,and the abrupt part and noise in the signal are effectively distinguished,the system noise is filtered out,and the signal to noise ratio is improved.It is Easy to leak judgments and positioning.Finally,a negative pressure wave pipeline leak detection system based on C# language and MATLAB language was developed.The hardware components and software design were respectively described.The hardware introduced the composition of pressure and flow sensors and related equipment.Selection;software,the main design of the five major program modules,including the system's initialization module,data acquisition and display module,data storage and history query module and leak detection and positioning module,and the software continuously debugging,while using the site collected The pipeline leaked negative pressure wave data and tested the system,confirming the reliability of the system.