基于CFD的天然气管道直板清管器内流场分析

清管作业在天然气管道中应用的越来越广泛,清管就是利用清管器推走管道内的沉积物和管道碎片,其目的是把管道内的杂物清除干净。定期清管可以保持管道中的流动通畅,降低管道内部压降,提高管道的流动效率。本文基于CFD（计算流体动力学）方法并利用Gambit及Fluent相关软件研究模拟了天然气管道直板清管器内部流场,模拟结果可显示清管器内部的压力变化流场和速度流场,研究结果为直板清管器的进一步稳定运行提供了理论基础。     

用于管道变形检测的新型泡沫智能清管器设计与试验验证

针对石油天然气管道完整性管理应用中,现有智能清管器通过性较差,聚氨酯泡沫清管器无法实现智能检测的问题,提出将力传感器搭载在泡沫清管器上,设计一种既能对管道进行变形检测又具备泡沫清管器良好通过性的新型泡沫智能清管器。通过力学性能理论分析和标定装置的试验验证发现:该泡沫清管器能感应管道变形数据,在变形量小于1/2传感器埋深时变形检测结果呈良好线性关系;采用内外层密度相同的清管器结构检测灵敏度不受传感器初始位置影响,可增加传感器埋深提升系统可靠性;采用内高外低的清管器结构可以通过减小传感器埋深和增大内层泡沫密度提升检测灵敏度,但应注意结构改变对检测系统可靠性的影响。该新型泡沫清管器可以实现变形的快速检测和定位,减少前期清管次数,节省成本;同时由于泡沫清管器的良好通过性,可以提升清管作业的安全性。     

智能管道清管器

从2003年开始．中国航空油料集团津京管道运输中心使用普通圆柱体清管器进行管道的清管作业．通过连续几个月的清管排淤，大大提高了管道的运行效率。现将其简略介绍，以飨读者。     

新型无源输油管道清管器的可行性研究

采用机械除蜡装置进行输油管道清管时,由于管道的弯曲、扭曲及蜡层较厚等原因,发生清管器的卡堵是一种普遍现象.文中提出了一种新型的防卡堵装置设计方案,包括尺寸、滚刀、流道、皮碗及排屑的设计,对高效清理作了验证,并进行了清管器可行性的理论分析.新型无源输油管道清管器能够满足防卡堵和高效清理的要求.     

长输管道弯管清管破裂失效分析

通过对某长输管线在清管过程中弯管段发生纵向开裂原因的分析,发现清管器的选型不合适,在经过弯管时与弯管外弧侧发生刮擦是导致弯管失效的根本原因。建议针对带有弯管的管线进行清管时,结合管线设计严格按照弯管的曲率半径和弯曲角度进行计算,确定清管器规格,并适当降低清管器的过盈量,缩短长度。     

清管阀在石油和天然气运输管线上的应用

介绍了清管阀的结构特征和工作原理,探讨了清管阀的结构设计和清管阀门内的压降,阐述了清管阀在管道中的功能及发展方向。     

论滤棒输送管道堵塞故障解决系统

常德烟机YF27型滤棒发射机所对接的输送管道,在接收机停止要料时,容易滞留部分滤棒在管道内,导致检测器报管道堵塞故障,使发射机无法正常工作,需要人工清管,造成滤棒浪费和影响卷接机的生产。为了解决此类故障,提出了一种有效而便捷的解决系统。该系统设计了一个四通清管器连接在输送管道前端,通过PLC控制电磁阀来实现的压缩空气的注入,解决了滤棒滞留在输送管道内的问题。结果表明实施该系统后,发射机由改进前平均7.5次/天的故障率次数降低到0次/天。结论证明该系统以最小的改造设备的代价,实现了预期的效果,解决管道堵塞。     

电子清管器探测定位成套仪器研制成功

为满足石油与天然气管道清管扫线,及对管道内部其他技术测量的需要,沈阳仪器仪表工艺研究所与四川石油输气处密切配合,研制成功QDY型电子清管器探测定位     

管道内的三维地理坐标检测

研究了利用管道清管器(PIG)搭载惯性测量单元(IMU)实现管道三维地理坐标测量的方法。该方法以捷联惯导系统(SINS)定位为主,并辅以校正信息的Kalman滤波估计算法来解决SINS计算的发散问题。首先,将测量装置搭载在PIG上,PIG在管道中运动的同时记录惯性信号。然后,经离线计算得到管道的三维地理坐标,并利用IMU的姿态倾角和里程轮速度对SINS计算的误差进行校正。最后,建立了9维状态量Kalman滤波模型方程,并利用扩展Kalman滤波算法进行求解。实验结果显示,该系统对于30m管道的测量精度为0.28m;表明通过加入校正算法,可以实现内检测条件下对管道三维地理坐标的精确测量。     

差压式管道机器人运动控制方法研究

为了提高管道内检测的精度与效率,研究了差压式管道机器人运动控制方法。针对当前差压式管道机器人机构设计中采用两端外套密封圈式清管器,由此导致速度难以控制的问题,按照驱动力与可控性指标设计了机器人的结构。在此基础上给出了差压式管道内检机器人动力学模型。对差压式管道机器人的运动控制进行了深入分析,给出了机器人与管壁取不同间隙条件下,机器人稳定运行速度与流体的流速之间的特性关系。根据分析结果设计了机器人的控制方案,给出了控制流程图,最后通过实验证明了所提方法的效果。     

Experimental study on dynamics of rotatable bypass-valve in speed control pig in gas pipeline

Periodically pigging of oil and gas pipelines for dewatering, cleaning and inspecting becomes a standard industry procedure. Speed control unit is needed to control the speed of the pig and keep it work at a moderate constant speed, especially in the large diameter and high pressure gas pipelines. Rotatable bypass-valve is a necessary part in speed regulating unit, which is used to control the speed of pig by changing the amounts of the bypass flow across the pig body. However, the dynamics of the bypass-valve is complexity and indeterminacy during bypassing. As a result, in this paper, an experiment facility is set up to simulate the real working condition and get the dynamic characteristics of bypass-valve. The relationship among the torque, the opening of bypass-valve and the differential pressure over bypass-valve can be obtained in this experiment, which can provide the references to make control algorithm for speed control pig.     

Optical method for flow patterns discrimination,slug and pig detection in horizontal gas liquid pipe

An optical method including infrared ray and laser was developed to discriminate flow pattern, and detect liquid slug and pig in horizontal gas–liquid pipe. Based on the principle that infrared ray attenuates differently during penetrating gas and liquid, the infrared ray method was developed to discriminate flow pattern and detect liquid slug. In experiment, infrared ray was emitted on one side of the transparent pipe, and detected on the other side. Simultaneously, a signal of output voltage that is proportional to the intensity of infrared ray detected was generated and recorded. A series of experiments in horizontal air/water loop were carried out to generate bubble, stratified smooth, wavy and intermittent flow, and the output voltages under the four flow patterns were analyzed. The flow patterns can be discriminated by characteristics of output voltage. Meanwhile, the velocity and frequency of liquid slug were measured by this method, and the results were consistent with that calculated by formulas. However, infrared ray is easily affected by interface between gas and liquid, a laser method was explored to detect pig. The laser method is similar to infrared ray, a laser beam was emitted and detected and then a signal of output voltage was recorded. The results from pigging experiments show that the laser method could correctly detect the passing of a pig. The combined use of infrared ray and laser method could rightly detect pig and pigging slug during pigging operation.     

Numerical study on leakage detection and location in a simple gas pipeline branch using an array of pressure sensors

Pressure signals measured in gas pipelines provide useful information for monitoring the status of pipeline network operations. This study numerically investigates leakage detection and location in a simple gas pipeline branch using transient signals from an array of pressure sensors. A pipeline network simulation model was developed and used to predict one-dimensional compressible flow in gas pipelines. Two monitoring methods were tested for leakage detection and location; these include cross-correlation monitoring and pressure differential monitoring. The performance and reliability of the two monitoring methods were numerically assessed based on simulation results for a simple pipeline branch operation with a prescribed leakage rate (5% of total flow rate in the gas pipeline).     

Verification of the Theoretical Model for Analyzing Dynamic Behavior of the PIG from Actual Pigging

This paper deals with verification of the theoretical model for dynamic behavior of Pipeline Inspection Gauge (PIG) traveling through high pressure natural gas pipeline. The dynamic behavior of the PIG depends on the differential pressure across its body. This differential pressure is generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. To analyze the dynamic behavior characteristics such as gas flow in pipeline, and the PIG position and velocity, not only the mathematical models are derived, but also the theoretical models must be certified by actual pigging experiment. But there is not any found results of research on the experimental certification for dynamic behavior of the PIG. The reason is why the fabrication of the PIG as well as, a field application are very difficult. In this research, the effectiveness of the introduced solution using the method of characteristics (MOC) was certified through field application. In-line inspection tool, 30” geometry PIG, was fabricated and actual pigging was carried out at the pipeline segment in Korea Gas Corporation (KOGAS) high pressure system, Incheon LT(LNG Terminal) -Namdong GS(Governor Station) line. Pigging is fulfilled successfully. Comparison of simulation results with experimental results show that the derived mathematical models and the proposed computational schemes are effective for predicting the position and velocity of the PIG with a given operational conditions of pipeline.     

清管技术及离心式压缩机组在西气东输系统上的应用

通过对兰州石化公司兰炼瓦斯系统即西气东输瓦斯系统运行情况和运行参数进行分析,确定了西气东输系统在线清管及采用离心式压缩机组输送瓦斯的方案,解决了系统管线积液和瓦斯带水导致冬季瓦斯输送不畅的问题,开辟了能源优化的最佳途径。     

A probe for in situ, remote, detection of defects in buried plastic natural gas pipelines

Several techniques are available to determine the integrity of in situ metal pipeline but very little is available in the literature to determine the integrity of plastic pipelines. Since the decade of the 1970s much of the newly installed gas distribution and transmission lines in the United States are fabricated from polyethylene or other plastic. A probe has been developed to determine the in situ integrity of plastic natural gas pipelines that can be installed on a traversing mechanism (pig) to detect abnormalities in the walls of the plastic natural gas pipeline from the interior. This probe has its own internal power source and can be deployed into existing natural gas supply lines. Utilizing the capacitance parameter, the probe inspects the pipe for flaws and records the data internally which can be retrieved later for analysis.     

基于2维设计的管线空间布局信息表达方法及其应用研究

提出用截切面映射图的方法来表达基于2维设计环境的管线空间布局信息，首先对管线实体在2维环境下的模型描述方式进行改进，使其含有完备的3维信息，然后通过交互设计出具有简单描述方式的虚拟截切面，并对管线图中任意位置的管线施加剖切操作，最后通过对截切面与各管线实体的虚拟求交来获取该剖切面上的管线截面分布图（即截切面映射图）及其相关信息，进而映射出相应的管线空间布局状态，实际应用表明，该方法可以较好地解决2维布管设计中的3维信息表达问题，提高了信息表达的直观性。     

在役管线无损检测设备的研究

为了管道的安全运行,在役管道必须定期进行检测,以免发生泄漏事故。本文首先介绍了常用的无损检测方法及应用,其次,对在役管线无损检测设备进行了深入的研究,具有一定的参考价值。     

Analysis of stress-corrosion flaws in main gas pipelines based on the results of in-tube nondestructive testing

The need for monitoring based on the results of in-tube magnetic testing of main gas pipelines is substantiated in this study. An analysis that is performed using the data of in-tube diagnostics of pipelines is the most complete and reliable source of information about the state of a main gas pipeline at the moment of monitoring. In particular, the efficiency of pig flaw detectors is clearly seen from the results of 5-yr nondestructive testing; the experience of inspection of main gas pipelines according to certain parameters is generalized.