在役天然气管道缺陷安全评定系统研发与应用

发布时间：2018-02-09 00:14

本文关键词： 天然气管道管道缺陷安全评定 CTOD计算 ANSYS模拟　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：天然气管道是陆地上大量输送天然气的唯一方式,世界天然气管道总长度不断增长。安全是输气管道的重要环节,而对于输气管道的缺陷评定和系统开发是确保天然气管道运行安全的关键因素。本文综述了断裂力学的发展及国内外含缺陷压力容器的评定方法,根据中国石油西南油气田公司输气管理处天然气管道的实际运营情况,基于“合于使用”的原则,在力学性能试验以及CTOD计算的基础上,以GB/T 19624-2004标准《在用含缺陷压力容器安全评定》为基础,形成了天然气管道缺陷安全评定体系,为天然气管多种缺陷的安全评定提供了有效方法,并通过数据库的应用及数学建模的思想将复杂的安全评定问题转化为基于漏磁检测数据的初步安全评定,并对三条天然气管线进行了安全评估,大大地缩短了安全评定的周期,并将结果与安全环保与技术监督研究院的报告进行了数据对比,主要研究工作如下：(1)跟踪和检索国内外针对于在役天然气管道缺陷现有的评定系统及相关领域最新进展对国内外的相关文献进行调研,比较、归纳相关文献的研究成果。(2)对国内外压力容器缺陷评定方法进行分析,以《在用含缺陷压力容器安全评定》GB/T 19624-2004标准为基础进行研究,形成了天然气管道缺陷安全评定方法(不’包括体积缺陷评价),为研发天然气管道缺陷安全评定系统打下了理论基础。(3)对X70钢、L415钢、16Mn钢三种国内主要采用的管道钢材进行了力学性能试验,并计算得到了CTOD值,为研发天然气管道缺陷安全评定提供技术参数。(4)根据CTOD试验以及漏磁检测结果,利用新研发的软件对3条天然气管线的所有的缺陷进行安全评定；并利用有限元软件ANSYS对凹陷缺陷进行分析,形成了评价报告。同时,将结果同国外软件结果进行了分析,证明了天然气管道缺陷安全评定方法和软件的可靠性。(5)利用有限元软件ANSYS对天然气管道焊接中的凹坑、错边、咬边、焊缝余高等体积缺陷对承载能力的影响进行有限元分析,得出各种缺陷对应力集中的影响,作为天然气管道体积缺陷评价的补充。(6)以天然气管道缺陷安全评定方法和VB程序设计为基础,开发了天然气管道缺陷安全评定系统(7)根据研发的天然气管道缺陷安全评定系统,对北内环支线管道、屏渠线管道、付纳线管道进行金属腐蚀特征分析、制造缺陷分析、金属物分析、凹陷分析及换焊缝异常分析,对未来腐蚀情况进行了预测,并制定了修复计划。
[Abstract]:Natural gas pipelines are the only way to transport natural gas in large quantities on land, and the total length of natural gas pipelines in the world continues to grow. Safety is an important part of gas pipelines. The defect assessment and system development of gas transmission pipeline are the key factors to ensure the safety of natural gas pipeline operation. This paper summarizes the development of fracture mechanics and the evaluation methods of pressure vessels with defects at home and abroad. According to the actual operation of the natural gas pipeline of CNPC Southwest Oil and Gas Field Company, based on the principle of "fit for use", and on the basis of mechanical performance test and CTOD calculation, Based on the GB/T 19624-2004 standard "Safety Assessment of pressure vessels with defects", a safety assessment system for natural gas pipeline defects is formed, which provides an effective method for the safety assessment of various defects in natural gas pipes. Through the application of database and the idea of mathematical modeling, the complex safety assessment problem is transformed into the preliminary safety assessment based on magnetic flux leakage detection data, and the safety assessment of three natural gas pipelines is carried out, which greatly shortens the period of safety assessment. The results were compared with the report of the Institute of Safety, Environmental Protection and Technology Supervision. The main research work is as follows: (1) tracking and retrieving the domestic and foreign literature on the existing assessment system for the defects of natural gas pipelines in service and the latest progress in related fields. Summarizing the research results of relevant literatures. (2) analyzing the defect assessment methods of pressure vessels both at home and abroad, and studying on the basis of GB/T 19624-2004 standard "Safety Assessment of pressure vessels with defects". The defect safety assessment method of natural gas pipeline (not including volume defect evaluation, which lays a theoretical foundation for the research and development of natural gas pipeline defect safety assessment system.) is formed for X70 steel L415 steel 16mn steel three kinds of pipeline mainly used in China. The mechanical properties of steel were tested. The CTOD value is calculated, which provides technical parameters for the safety assessment of defects in the R & D natural gas pipeline. (4) according to the results of CTOD test and magnetic flux leakage detection, all the defects of the three natural gas pipelines are evaluated by the newly developed software. The finite element software ANSYS is used to analyze the defect of the depression, and the evaluation report is formed. At the same time, the results are analyzed with the results of the foreign software. It is proved that the defect safety assessment method of natural gas pipeline and the reliability of software. 5) finite element analysis is carried out by using finite element software ANSYS to analyze the influence of the pit, the wrong edge, the edge bite and the residual high volume defect of the weld on the bearing capacity of the natural gas pipeline welding. The effects of various defects on stress concentration are obtained. As a supplement to the evaluation of volume defects in natural gas pipelines, the method of safety assessment of defects in natural gas pipelines and VB program design are used as the basis. The defect safety assessment system of natural gas pipeline is developed. According to the defect safety assessment system of natural gas pipeline developed, the metal corrosion characteristics of the north inner ring branch pipeline, the Ping canal line pipeline and the pay-in line pipeline are analyzed, and the defect analysis is made. Metal analysis, sag analysis and welding seam anomaly analysis are used to predict corrosion in the future and repair plan is made.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE88

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