基于声学激励的天然气管道水合物凝聚监测及定位技术

发布时间：2019-02-19 19:04

【摘要】：当今全球经济的飞速发展和人口数量的不断增长,导致全球范围内的能源需求量及消耗量持续增加。与其他化石燃料相比,使用天然气产生污染较低的同时还能产生更高的能量。管道输送是工业界运送天然气的最为普遍的方法,因此管道安全问题至关重要。通常天然气管道具有大管径、长距离和高压力的特点,一旦管道发生事故极易引发严重的后果。当天然气管道内部同时存在低温高压环境时,天然气水合物极易形成,增加了管道堵塞的风险,进而严重影响生产,引发安全事故。因此如何及时有效的清除管道内部的水合物凝聚是工业界亟需解决的问题。目前工业界对于天然气水合物堵塞管道的问题主要依靠五种方法:脱水法、压力法、加热法、机械法和化学法,但上述方法均有不可避免的缺点。针对上述问题,本文对基于声学激励的天然气管道内水合物凝聚监测及定位技术进行了初步探究,进行的主要工作如下:1、研究了声波在管道内的传播特性。2、构建了一套天然气管道内水合物(泄漏)安全检测系统,软件部分主要基于LabVIEW,系统主要由扬声器、麦克风、功率放大器和多功能数据采集卡构成。3、利用COMSOL多物理场仿真软件根据现有实验条件建立一系列的仿真模型进行探究,得到的仿真结果验证了实验原理及可行性。4、利用检测系统在实验管道上进行一系列实验,将实验与仿真结果进行对比,二者结果吻合较好,进一步证实本方法能对管道内部的异常情况进行定位,且定位精度较高。5、为了更好的区分反射信号,提出了基于小波包的检测信号特征提取方法。信号分析及特征提取结果表明,水合物凝聚与泄漏引起的反射信号的特征向量之间有较明显的区别,为后续模式识别奠定了基础。
[Abstract]:With the rapid development of global economy and the continuous increase of population, the global energy demand and consumption are increasing. The use of natural gas produces less pollution and more energy than other fossil fuels. Pipeline transportation is the most common method for transporting natural gas in industry, so pipeline safety is very important. Natural gas pipelines usually have the characteristics of large diameter, long distance and high pressure. When there is a low temperature and high pressure environment in the gas pipeline at the same time, the natural gas hydrate is easy to form, which increases the risk of pipeline blockage, and then seriously affects production and leads to safety accidents. Therefore, how to remove hydrate condensation effectively and timely is an urgent problem in industry. At present, the industry mainly relies on five methods for gas hydrate blocking pipeline: dehydration method, pressure method, heating method, mechanical method and chemical method. In order to solve the above problems, the gas hydrate agglomeration monitoring and location technology based on acoustic excitation is studied in this paper. The main work is as follows: 1. The propagation characteristics of acoustic wave in the pipeline are studied. 2. A gas hydrate (leakage) safety detection system in natural gas pipeline is constructed. The software is mainly based on LabVIEW, system, which consists of loudspeakers, microphones, power amplifiers and multi-function data acquisition cards. According to the existing experimental conditions, a series of simulation models are established by using COMSOL multi-physical field simulation software. The simulation results verify the principle and feasibility of the experiment. 4. A series of experiments are carried out on the experimental pipeline by using the detection system. Comparing the experimental results with the simulation results, the two results are in good agreement with each other. It is further proved that this method can locate the abnormal situation in the pipeline, and the accuracy of the localization is high. 5. In order to distinguish the reflected signals better, A detection signal feature extraction method based on wavelet packet is proposed. The results of signal analysis and feature extraction show that there are obvious differences between the characteristic vectors of the reflected signals caused by hydrate condensation and leakage, which lays a foundation for subsequent pattern recognition.
【学位授予单位】：天津科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE88

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