Abstract: In order to study the principle and technologies of acoustic leak detection for natural gas pipelines, an acoustic method is applied. A simulation model is established based on the field conditions to analyze and verify the generation mechanism of leakage acoustics. The field experiments are carried out based on the simulation results and measured signals are processed by joint time-frequency analyses including short time Fourier transform, wavelet transform, Hilbert-Huang transform and Generalized S transform to extract the characteristics that propagate a long distance. The characteristics are applied to detect the leak of long distance pipeline with satisfactory results. Finally the characteristics are used to locate leakages. The results show that the characteristics extracted by signal-processing from leakage acoustic signals can be applied to leak detection for long-distance natural gas pipelines.

Key words: natural gas, simulation, acoustic leak detection method, algorithm

摘要： 为研究输气管道音波法泄漏检测技术的基本原理和应用方法,从而为音波法泄漏检测技术在输气管道上的推广使用提供理论和实践基础,首先根据现场实验工况建立仿真模拟模型,对泄漏音波产生机理进行分析与验证;其次根据仿真模拟结果完成现场实验,并对现场实验数据进行了时频联合分析,包括短时傅里叶变换、小波变换、Hilbert-Huang变换和广义S变换,提取可用于远距离传播的音波信号特征;然后应用可远距离传播的信号特征,对长距离输气管道的泄漏进行检测,取得了较好的效果;最后采用提取的音波特征量进行泄漏定位,定位精度高.研究结果表明,通过信号处理得到泄漏音波信号特征可以用于长距离输气管道泄漏检测.

关键词: 天然气, 模拟, 音波法泄漏检测技术, 算法