大口径输气管道泄漏检测定位技术研究

发布时间：2018-05-18 00:42

本文选题：泄漏检测 + 定位　；参考：《武汉工程大学》2015年硕士论文

【摘要】：大口径长输管道是天然气远距离输送运用较多的方式,泄漏会造成长输管道运输中严重的安全问题,气体泄漏不仅会破坏环境,还会导致中毒、火灾、爆炸等严重事故,因此必须对正常运行的天然气管道进行安全检测。目前主要采用流量、压力等参数的变化对输气管道泄漏进行检测,此类方法容易受到管道运输状况的影响,且无法对管道的异常情况进行预警。本文分别研究了大管径的次声波和分布式光纤泄漏检测方法,结合两种泄漏检测方法的优势,达到降低误报率,识别与控制泄漏风险,减少安全事故发生的目的。本文展开了以下研究:1.通过分析管道泄漏次声波产生机理得出次声波是由流体与流体及流体与固体相互作用而形成,采用FLUENT软件对管道气体泄漏的状态进行模拟,从模拟泄漏口附近的气体压强分布和气体流速分布,可知泄漏口处将会产生一定的次声波信号,并根据Lighthill波动方程和FW-H方程分析泄漏次声波信号声压,最终得到管道泄漏音波信号。2.基于Mach-Zehnder分布式光纤泄漏检测原理,提出一种直线型Mach-Zehnder分布式光纤定位检测方法,搭建试验平台,将检测到的光电信号传输到Labview工作平台进行解调处理,获得检测结果,可知当外界出现干扰振动,该系统能较快速的检测到干扰,并能提前对管道的异常情况进行检测。3.选用小波分析方法对泄漏信号进行分析处理,针对泄漏信号的非平稳随机特性,分别采用阈值、小波包分解、互相关算法进行研究,比较三种算法的去噪效果,得出互相关算法不仅能有效的消去背景噪声,还能在一定程度上弱化突变处的噪声信号强度,有效提取泄漏瞬间的突变信号。
[Abstract]:Large-caliber long-distance pipeline is a kind of natural gas long-distance transportation. Leakage will cause serious safety problems in long-distance pipeline transportation. Gas leakage will not only damage the environment, but also lead to poisoning, fire, explosion and other serious accidents. Therefore, the normal operation of natural gas pipeline must be safely tested. At present, the variation of flow rate and pressure is mainly used to detect the leakage of gas pipeline. This kind of method is easy to be affected by the pipeline transportation condition, and the abnormal situation of the pipeline can not be forewarned. In this paper, the large diameter infrasonic wave and distributed optical fiber leak detection methods are studied respectively. Combining the advantages of the two leak detection methods, the purpose of reducing false alarm rate, identifying and controlling leakage risk and reducing the occurrence of safety accidents is achieved. In this paper, the following research is carried out: 1: 1. By analyzing the mechanism of pipeline leakage infrasound, it is concluded that infrasound is formed by the interaction of fluid and solid. The state of pipeline gas leakage is simulated by FLUENT software. By simulating the gas pressure distribution and gas velocity distribution near the leakage port, it can be seen that there will be a certain infrasonic wave signal at the leakage port, and the sound pressure of the leaked infrasonic wave signal is analyzed according to the Lighthill wave equation and FW-H equation. Finally, the pipeline leakage sonic signal. 2. Based on the principle of Mach-Zehnder distributed optical fiber leak detection, a linear Mach-Zehnder distributed fiber location detection method is proposed. The test platform is built, and the detected photoelectric signal is transmitted to the Labview working platform for demodulation processing, and the detection results are obtained. It is known that the system can detect the interference quickly and detect the abnormal situation of pipeline in advance when the external disturbance vibration occurs. The wavelet analysis method is used to analyze and process the leakage signal. According to the non-stationary random characteristic of the leakage signal, the threshold value, wavelet packet decomposition and cross-correlation algorithm are used to study respectively, and the denoising effect of the three algorithms is compared. It is concluded that the cross-correlation algorithm can not only effectively eliminate the background noise, but also weaken the noise signal intensity of the sudden change to a certain extent, and extract the abrupt signal of the leakage moment effectively.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE973.6

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