Monitoring And Locating Method Of Hydrate Agglomeration In Natural Gas Pipeline Based On Acoustic Active Excitation

With the rapid development of global economy, the continuous growth of global population, lead to global demand for energy and the consumption increasing. Use of fossil fuels lead to worsening human survival environment. Compared with other fossil fuels,natural gas can produce low pollution and more energy, plays an increasingly important role all over the world.Pipeline is one of the safest way to transport natural gas, and the pipeline safety is very important. Usually natural gas pipeline with large diameter, long distance, high pressure,the characteristics of huge throughput, the pipeline accident can cause serious security problems.Because the internal environment of the natural gas pipeline are low temperature and high pressure, leads to the natural gas hydrate formation extremely easily, greatly increases the risk of blockage cause the serious influence production and safety accidents. So how to timely and effective to get rid of the pipeline internal condensation of hydrate is the problem the industry needs to solve.The current problem of industry for natural gas hydrate is mainly rely on five kinds of methods: encapsulation-dehydration, pressure method, heating method, mechanical method and chemical method, but these methods all have inevitable shortcomings.According to the above problems, this paper based on the acoustic excitation condensation of hydrate in gas pipeline monitoring and locating technology has carried on the preliminary inquiry, the main work is as follows:1. Introduces the acoustic wave propagation in the pipe.2. Setting up a hydrate(leak) monitoring and locating system, this system is mainly designed by LabVIEW, is mainly composed of the speakers and microphone to power amplifier and multi-function data acquisition card.3. By using COMSOL under existing experimental conditions to establish a series of simulation models, the simulation results preliminary feasibility validation experiments.4. A series of experiments were conducted on the experimental pipeline by using this system, through comparing the results of experiment and simulation can be concluded that this method can to locate pipe internal anomalies with high accuracy. The characteristics of the abnormal situation at the same time the pipe are also affects the reflection signals, such as hydrate cross-sectional area of the size, length and the aperture size, etc.5. In order to distinguish the reflected signal better, is proposed based on wavelet packet method to extract feature vector, using the method of detecting signal feature extraction. Conclusions are as follows: condensation of hydrate and leakage caused by the characteristics of the reflected signal vector, have apparent difference between laid the groundwork for the subsequent pattern recognition.