输气管道截断阀安全关断的环道与仿真实验研究

发布时间：2018-06-01 21:46

本文选题：输气管道 + 截断阀　；参考：《西南石油大学》2015年硕士论文

【摘要】：线路截断阀作为管道运行的安全保障设备,能确保天然气发生泄漏和管道断裂时自行关闭。截断阀配备的气液联动执行机构是截断阀实现自行关闭的关键,其工作原理为：当管道破裂、泄漏时,压降速率会发生相应变化,线路截断阀执行机构感测到压降速率的变化后执行相应动作。科学合理的压降速率设定值对于截断阀的正常工作有重要影响,设置过小或过大的压降速率都不利于管道的安全。如果设置过大的压降速率,则一旦在相邻阀室中间出现断管事故,线路截断阀处感应不到压降速率变化,气液联动机构不能做出正确的响应,阀门不能关断(不关),会造成事故扩大,加剧经济损失和对环境的影响；如果设置的压降速率过小,则当管道压力波动时,容易引起误关断(误关),可能造成上游压缩机的停运,同时对安全平稳的供气造成严重影响。据统计自2007年至2011年,西气东输全线站场及阀室共发生约90次气液联动阀关断的情况,其中正常关断约70次,误关断约20次。忠武输气管线自2006年至2007年,误关断16次。本文针对天然气管线截断阀误动作及不能及时响应的原因及影响因素,截断阀安全关断压降速率设定值的合理选取及依据进行研究,以保障输气管道的安全、平稳运行。基于高压输气管道音波泄漏检测实验装置以及仿真软件平台,完成的主要工作内容如下：(1)分别在泄漏检测实验装置10mm及42mm两条管径上完成输气管道泄漏位置、泄漏孔径、管线压力等级等因素对压降速率及压降梯度的影响规律分析；(2)采用仿真方法,对泄漏工况和分输工况进行了模拟研究,并分析得到了泄漏工况和分输情况下不同工况压降速率随时间的变化情况,二者对比,得到较为理想的截断阀关断阈值；(3)通过仿真软件分别进行了压降速率和压降梯度随各影响因素的敏感性分析；(4)对阈值取值进行了算法拟合,得到了不同影响因素下的拟合公式；同时对压降梯度阈值取值进行了拟合,得到了相应的拟合公式,辅助应用于输气管道截断阀安全关断参数的设定。
[Abstract]:As a safety device for pipeline operation, line truncation valve can ensure natural gas leakage and pipeline breakage. The valve is equipped with a gas-liquid actuator, which is the key to the self-closing of the cut-off valve. Its working principle is that when the pipeline breaks and leaks, the pressure drop rate will change accordingly. The line truncation valve actuator detects the change of the pressure drop rate and performs the corresponding action. The scientific and reasonable pressure-drop rate has an important effect on the normal operation of the cut-off valve. Setting too small or too large a pressure drop rate is not conducive to the safety of the pipeline. If the pressure drop rate is set too large, once there is a pipe break accident in the middle of the adjacent valve chamber, the pressure drop rate will not be induced at the cut off valve, and the gas-liquid linkage mechanism will not be able to make the correct response. The valve cannot be closed (not closed, which will cause the accident to expand, aggravate the economic loss and the environmental impact; if the pressure drop rate is too small, when the pipe pressure fluctuates, It is easy to cause false shutdown, which may cause outage of upstream compressor and serious influence on safe and stable gas supply. According to statistics from 2007 to 2011, about 90 times of gas-liquid linkage valve shutoff occurred in the station yard and valve room of West-East Gas Transmission Line, including 70 normal shutoff and 20 wrong shutoff. From 2006 to 2007, Zhongwu gas pipeline was shut down 16 times by mistake. In this paper, in view of the causes and influencing factors of the maloperation of the truncation valve and the failure to respond in time, the reasonable selection and the basis of the pressure-drop rate of the cut off valve are studied in order to ensure the safety and smooth operation of the gas pipeline. Based on the acoustic wave leak detection experimental device and simulation software platform of high pressure gas transmission pipeline, the main work accomplished is as follows: 1) the leakage location and leak aperture of the gas transmission pipeline are completed on the two pipe diameters of 10mm and 42mm respectively. Analysis of the influence of pressure Grade on pressure drop rate and pressure gradient; A simulation method is used to simulate the leakage and distribution conditions. The variation of pressure drop rate with time under different conditions of leakage and transportation is analyzed and compared with each other. An ideal cut-off threshold of cut-off valve is obtained. The pressure drop rate and pressure gradient are analyzed with the sensitivity analysis of each factor by simulation software. (4) the algorithm fitting the threshold value is carried out, and the fitting formula under different influence factors is obtained. At the same time, the threshold value of the pressure gradient is fitted, and the corresponding fitting formula is obtained, which can be used to set the safe turn-off parameters of the cut off valve of the gas pipeline.
【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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