城市天然气管网泄漏检测与定位技术研究

发布时间：2019-07-08 14:07

【摘要】：随着环境污染的加重，人们开始寻找?种清洁、高效的新能源。天然气开始进入了人们的视线，日益受到国内、外的关注。天然气的主要运输手段是管道，由于其具有易燃易爆特性，管道的安全性就显得非常重要127】。随着我国经济的发展，能源结构的调整，城市天然气管网也在飞速发展。天然气的泄露检测与排除就显得尤为重耍。而城市燃气管网位于复杂多变的噪声环境中，具有压力低，多分支，多附件的特点，这就决定了其泄漏检测定位的难度很大[541。天然气管道的泄露检测与定位成为智慧城市天然气管网运行中亟待解决的关键技术之一。本研宄将广义声发射理论与混沌理论相结合，应叫于城市天然气管网的泄漏检测及定位。广义声发射[471是近些年发展起来的一个理论，用于研宄管壁中由泄油引发的应力波特性，该理论认为泄漏引发的信号是连续信号，可以对其进行连续捕捉，不必担心因错过时间而漏检。该特性是其与常规负压波理论的最大K别。基于混沌弱信号检测技术是信号处理领域中崭新的手段。本文融合声发射理论与混沌理论在天然气管网泄露的研究中，完成了以下主要工作与成果： 1)根据声发射检测技术，组建了天然气管道泄漏检测模拟系统，该系统由计算机、数据采集版、声发射传感器以及管道等组成。 2)采用广义声发射理论解释管壁屮由泄制引发的应力波现象，根据此理论研究了城市天然气管网屮、低压燃气管道泄漏信号的特点； 3)在混沌理论的驻础上，依据混沌系统对同频率的微弱周期信号极其敏感，，对噪声信号具有很强的免疫力的特性，研究了天然气管道强噪声中周期弱信号的检测方法’实现了在复杂多变的环境噪声中管道泄漏信号的检测； 4)根据单点泄漏模型以及互双谱理论,设计了实现天然气单点泄漏的定位方法。实验结果表明，该方法的正确性及在程上的可行性。该理论对检测范围存在单个泄漏点情况的检测及定位具有很氋的应用价值。通过大量现场实验以及仿真结果表明：混沌检测技术可以有效地在复杂多变的城市环境噪声中，实现城市中压及低压燃气管网的泄漏检测。将互双谱理论运用到城市地下燃气管网的泄漏定位中，可以有效地避免信号因噪声互相关而定位不准确的问题。结果表明该方法可以较准确的对管网的泄漏点进行定位，且定位精度较高。
[Abstract]:With the aggravation of the environmental pollution, people begin to look for? Clean and efficient new energy. The natural gas began to enter people's line of sight, and is increasingly attracted to the domestic and external attention. The main transport means of natural gas is the pipeline, because it has the inflammable and explosive property, the safety of the pipeline is very important 127]. With the development of our country's economy and the adjustment of the energy structure, the urban natural gas pipe network is developing rapidly. The leak detection and elimination of natural gas is particularly heavy. The city gas network is located in a complex and changeable noise environment, which has the characteristics of low pressure, multiple branches and multiple accessories, which determines the difficulty of its leak detection and positioning[541]. The leak detection and positioning of the natural gas pipeline is one of the key technologies to be solved in the operation of the natural gas pipe network of the intelligent city. In this paper, the theory of generalized acoustic emission and the theory of mixed noise are combined, and the leakage detection and location of the urban natural gas pipe network should be called. The generalized acoustic emission[471] is a theory developed in recent years, which is used to study the stress wave characteristics caused by the leakage of oil in the pipe wall. The theory is that the leakage-induced signal is a continuous signal and can be continuously captured without worrying about missing time due to missing time. The characteristic is that it is the maximum K of the conventional negative pressure wave theory. The detection of weak signal based on mixed signal is a new method in the field of signal processing. In this paper, the following main work and achievements have been completed in the study of the leakage of the natural gas pipe network by the theory of acoustic emission and the theory of mixed noise. 1) According to the acoustic emission detection technology, a gas pipeline leakage detection simulation system is formed, Edition, acoustic emission sensor, and piping, etc. (2) Using the theory of generalized acoustic emission to explain the stress wave phenomenon caused by the discharge of the pipe wall, the leakage signal of the gas pipeline of the urban natural gas pipe network and the low-pressure gas pipeline is studied according to the theory. the characteristics of (3) in the mix On the basis of the characteristic of the hybrid system to the weak periodic signal of the same frequency and the strong immunity of the noise signal, the method of detecting the periodic weak signal in the strong noise of the natural gas pipeline is studied, and the pipeline leakage in the complex and changeable environmental noise is realized. and 4) designing a positioning method for realizing the single-point leakage of the natural gas according to the single-point leakage model and the double-spectrum theory The experimental results show that the correctness of the method and the feasibility of the method are as follows: the detection and positioning of a single leakage point in the detection range It's worth it. It's through a lot of on-the-spot. The results of simulation and simulation show that the hybrid detection technology can effectively detect the leakage of medium-pressure and low-pressure gas pipe network in the complex and changeable urban environmental noise. The two-spectrum theory can be applied to the urban underground combustion. In the leakage positioning of the air pipe network, the problem of inaccurate positioning of the signal due to the noise cross-correlation can be effectively avoided. The result shows that the method can accurately determine the leakage point of the pipe network.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU996

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