管道微小泄漏内检测近场声信号特性研究  

Research on acoustic characteristic of the near field inside the pipe for small leakage detection

作　　者：郭世旭[1] 刘胜[2] 陈秀丽[2] 曾周末[1] 靳世久[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072 [2]中国石化化工销售有限公司华南分公司,广州510623

出　　处：《电子测量与仪器学报》2016年第6期834-844,共11页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(61473205);天津市科技兴海(KJXH2013-06)资助项目

摘　　要：声学内检测法有较高的管道泄漏检测灵敏度,而目前对泄漏声源附近近场声信号研究较少。基于Lighthill声类比的流场-声场混合的仿真方法,计算了不同泄漏孔径、不同管道内压下整个近场计算域的声场分布。仿真结果表明,泄漏声源是一种宽频噪声,在大于特征频率的频段,信号衰减,之前则保持稳定;管内声信号是泄漏声源在管壁束缚下的频散传播,在小于一阶模态频率内,传播平面波,大于一阶模态频率有多个模态的反射波。根据仿真分析结果,选取1~3.1 k Hz频段作为泄漏信号特征识别优选频段,得到泄漏量与该频段内能量呈正相关关系。搭建模拟泄漏测试平台,测试球形内检测样机,结果表明,该检测器可检测0.15 L/min泄漏量,实验结果与仿真结果可较好的吻合。研究结论对近距离听声内检测方法在声传感单元选型设计、声信号处理等方面有理论指导意义。The in-pipe acoustic sensing for leak detection has high sensitivity,but there is little research about the acoustic characteristic of the near field of the leak source. The acoustic characteristic of the near field inside the pipe for small leakage detection is studied by acoustic simulation and experiment. Through the hybrid aero-acoustic calculation process based on Lighthill＇s simulation,the near field acoustic distribution with different diameter of leak hole and different pipeline pressure were obtained. The simulation results show that the leak sound source is a broad band noise with a characteristic frequency,and above which the sound spectrum decays very much. The inpipe sound shows its dispersion characteristic because of the reflection from the pipe wall. Below the（ 1,0） mode cut-off frequency,only the plane wave is propagated,while there are many reflected wave when it is above. The frequency range from 1 k Hz to 3. 1 k Hz is selected as the research object for leak signal extraction. The relation between the energy signature parameter,OSPL,and leak rates is positively correlated. The prototype of spherical leak detector is tested on the leakage simulation test platform. It shows that the detector can detect the leak rates as low as 0. 15 L / min,and the experiment results can fit well with the simulated one.

关 键 词：微小泄漏 近场 内检测器 泄漏量 频散 

分 类 号：TE88[石油与天然气工程—油气储运工程]