【作者】 孙良；

【导师】 王建林；

【作者基本信息】 北京化工大学 ， 控制理论与控制工程， 2010， 博士

【摘要】 泄漏检测与定位系统是油气管道安全运行的重要组成部分。目前已有多种管道泄漏检测与定位方法,但在适用的泄漏工况和应用上都存在一定的局限性。基于模型的管道泄漏检测与定位方法依据流体的输送模型对泄漏量和泄漏位置进行预测,适用于突发泄漏、小泄漏和缓泄等多种泄漏工况的检测和定位。近年来,随着流量测量技术、数据采集与监控技术及装置的发展及应用,为基于模型的方法在油气管道泄漏检测中的进一步应用提供了基础。现有的基于模型的管道泄漏检测与定位方法定位时间过长,定位精度受模型参数影响较大,且在气体管道上的应用研究较少,因此对基于模型的泄漏检测与定位方法进行深入研究,促进其在管道泄漏检测中的应用具有重要的理论意义和应用价值。本文在详细分析现有基于模型的管道泄漏检测与定位方法的基础上,进一步研究基于稳态模型的管道泄漏检测与定位方法在油气管道上的应用,研究泄漏瞬态过程中的泄漏检测与定位方法,并对管道泄漏仿真建模方法进行探讨。对管道泄漏仿真建模方法进行研究,基于管道系统与电路系统的相似性,建立气体管道泄漏仿真模型,为泄漏检测与定位算法的验证提供必要的泄漏仿真数据,通过实际管道的泄漏实验验证了所建模型的有效性。对基于稳态模型的泄漏检测与定位方法在油气管道上的应用进行研究,针对气体管道,提出等温定位法和变步长龙格-库塔法,可分别用于等温和非等温气体管道的泄漏定位,并通过仿真和实验研究对模型简化的影响进行分析,为基于模型的气体管道泄漏检测与定位方法的应用提供参考和依据。针对稳态模型法受测量噪声影响较大的问题,采用基于最小二乘的最优泄漏点辨识方法对稳态模型法进行改进,实验研究表明改进后的稳态模型法可加快定位的收敛速度,增强了对噪声的抑制能力。对泄漏瞬态过程中信息产生和传播进行研究,提出一种基于泄漏瞬变模型的泄漏检测与定位方法,实现在管道泄漏瞬态过程中的准确定位。并综合稳态模型法和泄漏瞬变模型法的各自特点和优势,构建集成泄漏检测与定位方法。实验研究表明,所提出的泄漏瞬变模型法可有效利用泄漏的瞬变信息,在泄漏发生后最短时间内进行定位,所构建的集成泄漏检测与定位方法,既能保证泄漏检测与定位的实时性,又可实现泄漏检测的完整性。通过研究模型参数不均一性对泄漏定位的影响,提出一种管长等效变换方法,该方法将模型参数的不均一性转换为管段长度的变换,可在不改变定位算法复杂度的基础上进行定位误差的补偿,提高了模型法的定位精度。实际管道的实验研究进一步验证了所提出的补偿方法的有效性。本文所提出的等温定位法和变步长龙格-库塔法,促进了基于模型的方法在气体管道泄漏检测与定位中的应用,所提出的泄漏瞬变模型法和定位误差补偿方法提高了基于模型的管道泄漏检测与定位方法的实时性和准确性,促进了基于模型的方法在油气管道泄漏检测中的进一步发展和应用。更多还原

【Abstract】 Leak detection and location system plays an important role in the management of pipeline systems. In recent years, many kinds of leak detection and location methods have been developed and used, but most of them have limits in real applications, such as the applicability and detect ability. Based on the flow equations of pipeline, the model based leak detection and location method can determine the leak location and size of leakage, and is identified as a promising method in detecting burst, small and sluggish leaks. Recently, the widely used flow meters and Supervisory Control and Data Acquisition systems also provide the basis for applying model based leak detection and location method to oil and gas pipeline. However, the current model based method had difficulties in determining leak location during release transient process, leading to a long location time, and was subjected to severe noise and seldom addressed in gas pipelines. Its accuracy was influenced by the parameters of the model. Therefore, it is of great importance in both theory and application to research on the model based method and to improve the performance of the method.Based on the detailed analysis of current methods, the application of steady-state model based method to oil and gas pipeline has been futher studied, the method to detect and locate leaks during release transients has been researched, and the method to modeling a leaking pipline has been investigated as well.According to the analogous between the pipeline and the circuit, a method to modeling a leaking gas pipeline has been proposed. The simulation model established with the method can provide test data for leak detection and location algorithm. Experiments conducted on a real gas pipeline validate the the simulation model.The application of the steady-state model based method to oil and gas pipelines has been investigated, and the isothermal leak detection method and the variable-step Runge-Kutta method have been proposed for leak location in isothermal and non-isothermal gas pipelines respectively. Simulation research and experiments have been carried on to study the effect of the model simplification on the performance of the two methods. A modification for the steady-state model based method, named the optimal leak location identification based on the least square algorithm, has been presented and experiment results confirm the modification’s abability to suppress the noise and to speed up the convergence rate of leak localization. A new method based on the release transient model is proposed to detect and estimate the leakage point during the release transient, leading to a shorter leak location time and facilitating the trouble shooting. Combining the method based on steady-state model and method based on release transient model, an integrated method is constructed to take the advantages of the two methods. Simulation and experimental results showed that the release transient model based method can detect and locate leaks in shortest time after the release and the integrated method not only realized the leak localization in real time, but also ensured the integrity in leak detection.The effect of uneven distribution of pipeline parameter on the precision of leak estimation has been analyzed, a new approach, named equivalent transformation of the pipe length, which transform the uneven parameter distribution to the variation in pipe length, has been presented to compensate for the location error introduced by the uneven distributed parameter, and to improve the accuracy of the model based method. Experiments conducted on real pipelines verified the validation of the compensation method.The isothermal method and the variable-step Runge-Kutta method proposed in this paper enable the application of model based method to gas pipelines, the release transient model based method and the method to compensate for the location error improve the accuracy of the leak estimation and enable leak location in real time, promoting the development and application of model based method to oil and gas pipelines.更多还原